Since the founding of the American republic, Asia has been a key area of interest for the United States for both economic and security reasons. One of the first ships to sail under an American flag was the aptly named Empress of China, inaugurating the American role in the lucrative China trade in 1784. In the subsequent more than 200 years, the United States has worked under the strategic assumption that it was inimical to American interests to allow any single nation to dominate Asia. Asia constituted too important a market and was too great a source of key resources for the United States to be denied access. Thus, beginning with U.S. Secretary of State John Hay’s “Open Door” policy toward China in the 19th century, the United States has worked to prevent the rise of a regional hegemon, whether it was imperial Japan in Asia or the Soviet Union in Europe.

In the 21st century, the importance of Asia to the United States will continue to grow. Already, Asian markets absorb over a quarter of American exports in goods and services and, combined, support one-third of all American export-related jobs.1 This number is likely to grow.

Not only is Asia still a major market with two of the world’s most populous countries, but it is also a key source of vital natural resources and such goods as electronic components. Over 40 percent of the world’s hard drives, for example, are made in Thailand. The March 2011 earthquake that devastated Japan had global repercussions as supply chains for a variety of products from cars to computers were disrupted worldwide.

Asia is a matter of more than just economic concern, however. Several of the world’s largest militaries are in Asia, including those of China, India, North and South Korea, Pakistan, Russia, and Vietnam. The United States also maintains a network of treaty alliances and security partnerships, as well as a significant military presence, in Asia. Five Asian states (China, North Korea, India, Pakistan, and Russia) possess nuclear weapons.

The region is a focus of American security concerns both because of the presence of substantial military forces and because of the legacy of conflict. The two major “hot” wars the United States fought during the Cold War were both in Asia—Korea and Vietnam. Moreover, the Asian security environment is unstable. For one thing, the Cold War has not ended in Asia. Of the four states divided between Communism and democracy by the Cold War, three (China, Korea, and Vietnam) were in Asia. Neither the Korean nor the China–Taiwan situation was resolved despite the fall of the Berlin Wall and the collapse of the Soviet Union.

The Cold War itself was an ideological conflict layered atop long-standing—and still lingering—historical animosities. Asia is home to several major territorial disputes, among them:

  • Northern Territories/Southern Kuriles (Japan and Russia);
  • Senkakus/Diaoyutai/Diaoyu Dao (Japan, China, and Taiwan);
  • Dok-do/Takeshima (Korea and Japan);
  • Paracels/Xisha Islands (Vietnam, China, and Taiwan);
  • Spratlys/Nansha Islands (China, Taiwan, Vietnam, Brunei, Malaysia, and the Philippines);
  • Kashmir (India and Pakistan); and
  • Aksai Chin and parts of the Indian state of Arunachal Pradesh (India and China).

Even the various names applied to the disputed territories reflect the fundamental differences in point of view, as each state refers to the disputed areas under a different name. Similarly, different names are applied to the various major bodies of water: for example, “East Sea” or “Sea of Japan” and “Yellow Sea” or “West Sea.”

These disputes over names also reflect the broader tensions rooted in historical animosities—enmities that still scar the region. Most notably, Japan’s actions in World War II remain a major source of controversy, particularly in China and South Korea, where debates over issues such as what is incorporated in textbooks and governmental statements prevent old wounds from completely healing. Similarly, a Chinese claim that much of the Korean peninsula was once Chinese territory aroused reactions in both Koreas. The end of the Cold War did little to resolve any of these underlying disagreements.

It is in this light that one should consider the lack of a political–security architecture, or even much of an economic one, undergirding East Asia. Despite substantial trade and expanding value chains among the various Asian states, as well as with the rest of the world, formal economic integration is limited. There is no counterpart to the European Union or even to the European Economic Community, just as there is no parallel to the European Coal and Steel Community, the precursor to European economic integration.

The Association of Southeast Asian Nations (ASEAN) is a far looser agglomeration of disparate states, although they have succeeded in expanding economic linkages among themselves over the past 49 years. Less important to regional stability has been the South Asia Association of Regional Cooperation (SAARC), which includes Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. The SAARC is largely ineffective, both because of the lack of regional economic integration and because of the historical rivalry between India and Pakistan. Also, despite attempts, there is still no Asia-wide free trade agreement (although the Trans-Pacific Partnership, if passed, and the Regional Comprehensive Economic Partnership would help to remedy this gap to some extent).

Similarly, there is no equivalent of NATO, despite an ultimately failed mid-20th century effort to forge a parallel multilateral security architecture through the Southeast Asia Treaty Organization (SEATO). Regional security entities such as the Five Power Defence Arrangement (involving the United Kingdom, Australia, New Zealand, Malaysia, and Singapore in an “arrangement,” not an alliance) or discussion forums such as the ASEAN Regional Forum and the ASEAN Defense Ministers-Plus Meeting have been far weaker. Nor did an Asian equivalent of the Warsaw Pact arise. Instead, Asian security has been marked by a combination of bilateral alliances, mostly centered on the United States, and individual nations’ efforts to maintain their own security.

Important Alliances and Bilateral Relations in Asia

For the United States, the keys to its position in the Western Pacific are its alliances with Japan, the Republic of Korea, the Philippines, Thailand, and Australia. These five alliances are supplemented by very close security relationships with New Zealand, Afghanistan, Pakistan, and Singapore and evolving relationships with other nations in the region like India, Vietnam, Malaysia, and Indonesia. The U.S. also has a robust unofficial relationship with Taiwan.

The United States enjoys the benefit of sharing common weapons and systems with many of its allies, which facilitates interoperability. Many nations, for example, have equipped their infantries with M-16/M-4–based infantry weapons (and share the 5.56mm caliber); F-15 and F-16 combat aircraft; and LINK-16 data links. Consequently, in the event of conflict, the various air, naval, and even land forces will be capable of sharing information in such key areas as air defense and maritime domain awareness. This advantage is further expanded by the constant ongoing range of both bilateral and multilateral exercises, which acclimates various forces to operating together and familiarizes both American and local commanders with each other’s standard operating procedures (SOPs), as well as training and tactics.

Japan. The U.S.–Japan defense relationship is a critical centerpiece in the American network of relations in the Western Pacific. The U.S.–Japan Treaty of Mutual Cooperation and Security, signed in 1960, provided for a deep alliance between two of the world’s largest economies and most sophisticated military establishments, and changes in Japanese defense policies are now enabling an even greater level of cooperation on security issues between the two allies and others in the region.

Since the end of World War II, Japan’s defense policy has been distinguished by Article 9 of its constitution. This article, which states in part that “the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes,”2 in effect prohibits the use of force by Japan’s governments as an instrument of national policy. It also has led to several other associated policies.

One such policy is a prohibition on “collective self-defense.” Japan recognized that nations have a right to employ their armed forces to help other states defend themselves (i.e., to engage in collective defensive operations) but rejected that policy for itself: Japan would employ its forces only in defense of Japan. In 2015, this changed. The U.S. and Japan revised their defense cooperation guidelines, and the Japanese passed necessary legislation to allow Japan to exercise collective self-defense in cases involving threats to the U.S. and multilateral peacekeeping operations.

A similar policy decision was made regarding Japanese arms exports. For a variety of economic and political reasons, Tokyo has chosen to rely on domestic production to meet most of its military requirements. At the same time, until very recently, it chose to limit arms exports, banning them entirely to:

  • Communist bloc countries;
  • Countries that are placed by the U.N. Security Council under arms exports embargoes; and
  • Countries that are involved in or likely to be involved in international conflicts.3

The relaxation of these export rules in 2014 enabled Japan, among other things, to pursue (ultimately unsuccessfully) an opportunity to build new state-of-the-art submarines in Australia, for Australia, and possible sales of amphibious search and rescue aircraft to the Indian navy. Japan has also sold multiple patrol vessels to the Philippine and Vietnamese Coast Guards.

Tokyo relies heavily on the United States for its security. In particular, it depends on the United States to deter nuclear attacks on the home islands. The combination of the pacifist constitution and Japan’s past (i.e., the atomic bombings of Hiroshima and Nagasaki) has forestalled much public interest in obtaining an independent nuclear deterrent. Similarly, throughout the Cold War, Japan relied on the American conventional and nuclear commitment to deter Soviet (and Chinese) aggression.

As part of its relationship with Japan, the United States maintains some 54,000 military personnel and another 8,000 Department of Defense civilian employees in Japan under the rubric of U.S. Forces Japan (USFJ).4 These forces include a forward-deployed carrier battle group (centered on the USS Ronald Reagan); a submarine tender; an amphibious assault ship at Yokosuka; and the bulk of the Third Marine Expeditionary Force (III MEF) on Okinawa. U.S. forces exercise regularly with their Japanese counterparts; in recent years, this collaboration has expanded from air and naval exercises to practicing amphibious operations together.

Supporting the American presence is a substantial American defense infrastructure established throughout Japan, including Okinawa. The array of major bases provides key logistical and communications support for U.S. operations throughout the Western Pacific, cutting travel time substantially compared with deployments from Hawaii or the American West Coast. They also provide key listening posts on Russian, Chinese, and North Korean military operations. This is likely to be supplemented by Japan’s growing array of space systems, including new reconnaissance satellites.

The Japanese government defrays a substantial portion of the cost of the American presence. At present, the government of Japan provides some $2 billion annually to support the cost of USFJ.5 These funds cover a variety of expenses, including utility and labor costs at U.S. bases, improvements to U.S. facilities in Japan, and the cost of relocating training exercises away from populated areas in Japan.

U.S.–Japanese defense cooperation is undergirded not only by the mutual security treaty, but also by the new 2015 U.S.–Japan Defense Guidelines. The guidelines allow both the geographic scope and the nature of Japan’s security contributions to include operations “involving the use of force to respond to situations where an armed attack against a foreign country that is in a close relationship with Japan occurs.”6 The revisions make Japan a fuller partner in the alliance.

At least since the 1990 Gulf War, the United States had sought to obtain expanded Japanese participation in international security affairs. This effort had generally been resisted by Japan’s political system, based on the view that Japan’s constitution, legal decisions, and popular attitudes all forbid such a shift. Attempts to expand Japan’s range of defense activities, especially away from the home islands, have often been met by vehement opposition from Japan’s neighbors, especially China and South Korea, due to unresolved differences on issues ranging from territorial claims and boundaries to historical grievances and Japanese visits to the Yasukuni Shrine. Even with the changes, these issues will doubtless continue to constrain Japan’s contributions to the alliance.

These issues have been sufficient to torpedo efforts to improve defense cooperation between Seoul and Tokyo, a fact highlighted in 2012 by South Korea’s last-minute decision not to sign an agreement to share sensitive military data, including details about the North Korean threat to both countries.7 In December 2014, the U.S., South Korea, and Japan signed a minimalist military data-sharing agreement limited only to information on the North Korean military threat and requiring both allies to pass information through the United States military. Similar controversies, rooted in history as well as in contemporary politics, have also affected Sino–Japanese relations and, to a lesser extent, Japanese ties to some Southeast Asian states.

Nonetheless, Prime Minister Shinzō Abe has pushed through a reinterpretation of the legality of Japanese participation in “collective self-defense” situations, as well as a loosening of restrictions on arms sales. The combination of reforms provides the legal foundation for much greater Japanese interaction with other states in defense arenas, including joint production of weapons and components and the potential for interaction with foreign military forces.8

Republic of Korea. The United States and the Republic of Korea (ROK) signed the Mutual Defense Treaty in 1953. That treaty codified the relationship that had grown from the Korean War, when the United States dispatched troops to help South Korea defend itself against invasion by Communist North Korea. Since then, the two states have forged an enduring alliance that supplements a substantial trade and economic relationship that includes a free trade agreement.

The United States currently maintains some 28,500 troops in Korea, the largest concentration of American forces on the Asian mainland. This is centered mainly on the U.S. 2nd Infantry Division and a significant number of combat aircraft.

The U.S.–ROK defense relationship involves one of the more integrated and complex command-and-control structures. A United Nations Command (UNC) established in 1950 was the basis for the American intervention, and it remained in place after the armistice was signed in 1953. UNC has access to a number of bases in Japan in order to support U.N. forces in Korea. In concrete terms, however, it only oversaw South Korean and American forces as other nations’ contributions were gradually withdrawn or reduced to token elements.

In 1978, operational control of frontline South Korean and American military forces transitioned from UNC to Combined Forces Command (CFC). Headed by an American officer (who is also the Commander, U.N. Command), CFC reflects an unparalleled degree of U.S.–South Korean military integration. Similarly, the system of Korean Augmentees to the United States Army (KATUSA), which places South Korean soldiers into American units assigned to Korea, allows for a degree of tactical-level integration and cooperation that is atypical.

Current command arrangements for the U.S. and ROK militaries are for CFC to exercise operational control (OPCON) of all forces on the peninsula in time of war, while peacetime control rests with respective national authorities (although the U.S. exercises peacetime OPCON over non-U.S., non-ROK forces located on the peninsula). In 2003, South Korean president Roh Moo-hyun, as agreed with the U.S., began the process of transferring wartime operational control from CFC to South Korean commanders, thereby establishing the ROK military as fully independent of the United States. This decision engendered significant opposition within South Korea, however, and raised serious military questions about the impact on unity of command. Coupled with various North Korean provocations (including a spate of missile tests as well as attacks on South Korean military forces and territory in 2010), Washington and Seoul agreed in late 2014 to postpone wartime OPCON transfer.9

The domestic political constraints under which South Korea’s military operates are less stringent than those that govern the operations of the Japanese military. Thus, South Korea rotated several divisions to fight alongside Americans in Vietnam. In the first Gulf War, the Iraq War, and Afghanistan, South Korea limited its contributions to non-combatant forces and monetary aid. The focus of South Korean defense planning remains on North Korea, however, especially as Pyongyang has deployed its forces in ways that optimize a southward advance. Concerns about North Korea have been heightened in recent years in the wake of the sinking of the South Korean frigate Cheonan and the shelling of Yongpyeong-do, perhaps the most serious incident in decades. Moreover, in the past several conflicts (e.g., Operation Iraqi Freedom), Seoul has not provided combat forces, preferring instead to send humanitarian and non-combatant assistance.

Over the past several decades, the American presence on the peninsula has slowly declined. In the early 1970s, President Richard Nixon withdrew the 7th Infantry Division, leaving only the 2nd Infantry Division on the peninsula. Those forces have been positioned farther back so that there are few Americans deployed on the Demilitarized Zone (DMZ).

Washington has agreed to maintain 28,500 troops in the ROK. These forces regularly engage in major exercises with their ROK counterparts, including the Key Resolve and Foal Eagle series. Both of these series involve the actual deployment of a substantial number of forces and are partly intended to deter Pyongyang, as well as to give U.S. and ROK forces a chance to practice operating together.

The ROK government also provides substantial resources to defray the costs of U.S. Forces–Korea. It provides some $900 million annually in either direct funding or in-kind support, covering cost-sharing for labor, logistics, and improvements in facilities.10

The Philippines. America’s oldest defense relationship in Asia is with the Philippines. The United States seized the Philippines from the Spanish over a century ago as a result of the Spanish–American War and a subsequent conflict with Philippine indigenous forces. But the U.S., unlike other colonial states, also put in place a mechanism for the Philippines to gain its independence, transitioning through a period as a commonwealth until the archipelago was granted independence in 1946. Just as important, substantial numbers of Filipinos fought alongside the United States against Japan in World War II, establishing a bond between the two peoples. Following World War II and after assisting the newly independent Filipino government against the Communist Hukbalahap movement in the 1940s, the United States and the Philippines signed a mutual security treaty.

For much of the period between 1898 and the end of the Cold War, the largest American bases in the Pacific were in the Philippines, centered around the U.S. Navy base in Subic Bay and the complex of airfields that developed around Clark Field (later Clark Air Base). While the Philippines have never had the ability to provide substantial financial support for the American presence, the base infrastructure was unparalleled, providing replenishment and repair facilities and substantially extending deployment periods throughout the East Asian littoral.

These bases were often centers of controversy, however, as they were reminders of the colonial era. In 1991, a successor to the Military Bases Agreement between the U.S. and the Philippines was submitted to the Philippine Senate for ratification. The Philippines, after a lengthy debate, rejected the treaty, compelling American withdrawal from Philippine bases. Coupled with the effects of the 1991 eruption of Mount Pinatubo (which devastated Clark Air Base and damaged many Subic Bay facilities) and the end of the Cold War, closure of the bases was not seen as fundamentally damaging to America’s posture in the region.

Moreover, despite the closing of the American bases and consequent slashing of American military assistance, U.S.–Philippine military relations remained close, and assistance began to increase again after 9/11 as U.S. forces assisted the Philippines in countering Islamic terrorist groups, including Abu Sayyaf, in the south of the archipelago. From 2002–2015, the U.S. rotated 500–600 special operations forces regularly through the Philippines to assist in counterterrorism operations. That operation, Joint Special Operations Task Force-Philippines (JSOTF-P), closed in the first part of 2015, but the U.S. presence in Mindanao continues at reduced levels. Another 6,000 participate in combined exercises with Philippine troops.11

In 2014, the United States and the Philippines announced a new Enhanced Defense Cooperation Agreement (EDCA), which allows for an expanded American presence in the archipelago,12 and in early 2016, they agreed on five specific bases subject to the agreement. Under the EDCA, U.S. forces will rotate through these locations on an expanded basis, allowing for a more regular presence (but not new, permanent bases) in the islands, and will engage in more joint training with AFP forces. The agreement also facilitates the provision of humanitarian assistance and disaster relief (HA/DR). The United States also agreed to improve the facilities it uses and to transfer and sell more military equipment to the AFP to help it modernize. This is an important step, as the Philippine military has long been one of the weakest in the region, despite the need to defend an incredibly large expanse of ocean, shoreline, and territory.

One long-standing difference between the U.S. and the Philippines has been the application of the U.S.–Philippine Mutual Defense Treaty to disputed islands in the South China Sea. While the U.S. has long maintained that the treaty does not extend American obligations to disputed areas and territories, Filipino officials occasionally have held otherwise.13 The EDCA does not settle this question, but the growing tensions in the South China Sea, including in recent years at Scarborough Shoal, have highlighted Manila’s need for greater support from and cooperation with Washington. Moreover, the U.S. government has long been explicit that any attack on Philippine government ships or aircraft, or on the Philippine armed forces, would be covered under the Treaty, “thus separating the issue of territorial sovereignty from attack on Philippine military and public vessels.”14

In 2016, the Philippines elected a new, very unconventional President, Rodrigo Duterte, to a six-year term. His rhetorical challenges to current priorities in the U.S.–Philippines alliance raise questions about the trajectory of the alliance and the sustainability of new initiatives that are important to it.

Thailand. The U.S.–Thai security relationship is built on the 1954 Manila Pact, which established the now-defunct Southeast Asia Treaty Organization, and the 1962 Thanat–Rusk agreement. These were supplemented by the 2012 Joint Vision statement for U.S.–Thai relations. In 2003, Thailand was designated a “major, non-NATO ally,” giving it improved access to American arms sales.

Thailand’s central location has made it an important component of the network of U.S. alliances in Asia. During the Vietnam War, a variety of American aircraft were based in Thailand, ranging from fighter-bombers and B-52s to reconnaissance aircraft. In the first Gulf War and again in the Iraq War, some of those same air bases were essential for the rapid deployment of American forces to the Persian Gulf.

U.S. and Thai forces regularly exercise together, most notably in the annual Cobra Gold exercises, first begun in 1982. This builds on a partnership that began with the dispatch of Thai forces to the Korean War, where over 1,200 Thai troops died (out of some 6,000 deployed). The Cobra Gold exercises are among the world’s largest multilateral military exercises.

U.S.–Thai relations have been strained in recent years as a result of domestic unrest and two coups in Thailand. This strife has limited the extent of U.S.–Thai military cooperation, as U.S. law prohibits U.S. funding for many kinds of assistance to a foreign country in which a military coup deposes a duly elected head of government. Nonetheless, the two states continue to cooperate, including in joint military exercises and in the area of counterterrorism. The Counter Terrorism Information Center (CTIC) continues to allow the two states to share vital information about terrorist activities in Asia. CTIC is alleged to have played a key role in the capture of the leader of Jemaah Islamiyah, Hambali, in 2003.15

Thailand has also been drawing closer to the People’s Republic of China (PRC). This process has been underway since the end of the Vietnam War but is accelerating due to expanding economic relations between the two states. Between 2005 and 2010, the value of trade between the two states doubled. Today, China is Thailand’s leading trading partner.16

The Thai and Chinese militaries also have improved relations over the years. Intelligence officers began formal meetings in 1988. Thai and Chinese military forces have engaged in joint counterterrorism exercises since 2007, and the two nations’ marines have exercised jointly since 2010.17 Thai–Chinese military relations may have accelerated as a result of the U.S. restrictions imposed in the wake of Thai political instability.

Australia. Australia is one of the most important American allies in the Asia–Pacific. U.S.–Australia security ties date back to World War I, when U.S. forces fought under Australian command on the Western Front. These ties deepened during World War II when, after Japan commenced hostilities in the Western Pacific, Australian forces committed to the North Africa campaign were not returned to defend the continent—despite British promises to do so. As Japanese forces attacked the East Indies and secured Singapore, Australia turned to the United States to bolster its defenses, and American and Australian forces subsequently cooperated closely in the Pacific War. Those ties and America’s role as the main external supporter for Australian security were codified in the Australia–New Zealand–U.S. (ANZUS) pact of 1951.

A key part of the Obama Administration’s “Asia pivot” was to rotate additional United States Air Force units and Marines through Northern Australia.18 Eventually expected to total some 2,500 troops, the initial contingents of Marine forces are based near the northern city of Darwin. The two sides continue to negotiate the terms of the full deployment, which it is now estimated will be complete by 2020.19 Meanwhile, the two nations engage in a variety of security cooperation efforts, including joint space surveillance activities. These were codified in 2014 with an agreement that allows sharing of space information data among the U.S., Australia, the U.K., and Canada.20

The two nations’ chief defense and foreign policy officials meet annually in the Australia–United States Ministerial (AUSMIN) process to address such issues of mutual concern as security developments in the Asia–Pacific region, global security and development concerns, and bilateral security cooperation.21 Australia has also granted the United States access to a number of joint facilities, including space surveillance facilities at Pine Gap and naval communications facilities on the North West Cape of Australia.22

Australia and the United Kingdom are two of America’s closest partners in the defense industrial sector. In 2010, the United States approved Defense Trade Cooperation Treaties with Australia and the U.K. These treaties allow for the expedited and simplified export or transfer of certain defense services and items between the U.S. and its two key partners without the need for export licenses or other approvals under the International Traffic in Arms Regulations. This also allows for much greater integration among the American, Australian, and British defense industrial establishments.23

Singapore. Although Singapore is not a security treaty ally of the United States, it is a key security partner in the region. In 2005, the close defense relationship was formalized with the Strategic Framework Agreement (SFA), and in 2015, it was expanded with the U.S.–Singapore Defense Cooperation Agreement (DCA).

The 2005 SFA was the first agreement of its kind since the end of the Cold War.24 It built on the 1990 Memorandum of Understanding Regarding United States Use of Facilities in Singapore, as amended, which allows for U.S. access to Singaporean military facilities.25 The 2015 DCA establishes “high-level dialogues between the countries’ defense establishments” and a “broad framework for defense cooperation in five key areas, namely in the military, policy, strategic and technology spheres, as well as cooperation against non-conventional security challenges, such as piracy and transnational terrorism.”26

New Zealand. For much of the Cold War, U.S. defense ties with New Zealand were similar to those between America and Australia. As a result of controversies over U.S. Navy employment of nuclear power and the possibility of deployment of U.S. naval vessels with nuclear weapons, the U.S. suspend its obligations to New Zealand under the 1951 ANZUS Treaty. Defense relations improved, however, in the early 21st century as New Zealand committed forces to Afghanistan and also dispatched an engineering detachment to Iraq. The 2010 Wellington Declaration and the 2012 Washington Declaration, while not restoring full security ties, allowed the two nations to resume high-level defense dialogues. In 2013, U.S. Secretary of Defense Chuck Hagel and New Zealand Defense Minister Jonathan Coleman announced the resumption of military-to-military cooperation,27 and in July 2016, the U.S. accepted an invitation from New Zealand to make a single port call, reportedly with no change in U.S. policy to confirm or deny the presence of nuclear weapons on board.28 This may portend a longer-term solution to the nuclear impasse between the two nations.

Taiwan. When the United States shifted its recognition of the government of China from the Republic of China (on Taiwan) to the People’s Republic of China (the mainland), it declared certain commitments concerning the security of Taiwan. These commitments are embodied in the Taiwan Relations Act (TRA) and the subsequent “Six Assurances.”

The TRA is an American law and not a treaty. Under the TRA, the United States maintains programs, transactions, and other relations with Taiwan through the American Institute in Taiwan (AIT). Except for the U.S.–China Mutual Defense Treaty, which had governed U.S. security relations with Taiwan, all other treaties and international agreements made between the Republic of China and the United States remain in force. (The Sino–U.S. Mutual Defense Treaty was terminated by President Jimmy Carter following the shift in recognition to the PRC.)

Under the TRA, it is the policy of the United States “to provide Taiwan with arms of a defensive character.” The TRA also states that the U.S. will “make available to Taiwan such defense articles and services in such quantity as may be necessary to enable Taiwan to maintain a sufficient self-defense capability.” The U.S. has implemented these provisions of the TRA through sales of weapons to Taiwan.

The TRA states that it is U.S. policy to “consider any effort to determine the future of Taiwan by other than peaceful means, including by boycotts or embargoes, a threat to the peace and security of the Western Pacific area and of grave concern to the United States.”29 It also states that it is U.S. policy to “maintain the capacity of the United States to resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people on Taiwan.”30

The TRA requires the President to inform Congress promptly of “any threat to the security or the social or economic system of the people on Taiwan and any danger to the interests of the United States arising therefrom.” The TRA then states: “The President and the Congress shall determine, in accordance with constitutional processes, appropriate action by the United States in response to any such danger.”

Supplementing the TRA are the “Six Assurances” issued by President Ronald Reagan in a secret July 1982 memo, subsequently publicly released and the subject of a Senate hearing. These six assurances were intended to moderate the third Sino–American communique, itself generally seen as one of the “Three Communiques” that form the foundation of U.S.–PRC relations. These assurances of July 14, 1982, were as follows:

  1. In negotiating the third Joint Communique with the PRC, the United States:
  2. has not agreed to set a date for ending arms sales to Taiwan;
  3. has not agreed to hold prior consultations with the PRC on arms sales to Taiwan;
  4. will not play any mediation role between Taipei and Beijing;
  5. has not agreed to revise the Taiwan Relations Act;
  6. has not altered its position regarding sovereignty over Taiwan;
  7. will not exert pressure on Taiwan to negotiate with the PRC.31

Although the United States sells Taiwan a variety of military equipment, it does not engage in joint exercises with the Taiwan armed forces. Some Taiwan military officers, however, do receive training in the United States, attending American professional military education institutions. There also are regular high-level meetings between senior U.S. and Taiwan defense officials, both uniformed and civilian. The United States does not maintain any bases in Taiwan or its territories.

Vietnam, Malaysia, and Indonesia. The U.S. has security relationships with several key Southeast Asian countries, none of them as extensive and formal as its relationship with Singapore and its treaty allies but all still of growing significance. The U.S. “rebalance” to the Pacific has incorporated a policy of “rebalance within the rebalance” that has included efforts to expand relations with this second tier of American security partners.

Since shortly after the normalization of diplomatic relations between the two countries in 1995, the U.S. and Vietnam also have normalized their defense relationship, albeit very slowly. The relationship was codified in 2011 with a Memorandum of Understanding “advancing bilateral defense cooperation” that covers five areas of operations, including maritime security. The most significant development in security ties over the past several years has been the relaxation of the ban on sales of arms to Vietnam. In the fall of 2014, the U.S. lifted the embargo on maritime security–related equipment, and then on President Barack Obama’s visit to Hanoi in 2016, it lifted the ban completely. This full embargo had long served as a psychological obstacle to Vietnamese cooperation on security issues. Lifting it does not necessarily change the nature of the articles likely to be sold, and no transfers, including P-3 maritime patrol aircraft, discussed since the relaxation of the embargo two years ago, have been made. Lifting the embargo does, however, expand the potential of the relationship and better positions the U.S. to compete with Chinese and Russian positions there. The Joint Statement from President Obama’s visit also memorialized a number of other improvements in the U.S.–Vietnam relationship, including the Cooperative Humanitarian and Medical Storage Initiative (CHAMSI), which will advance cooperation on humanitarian assistance and disaster relief by, among other things, prepositioning related American equipment in Danang, Vietnam.32

There remain significant limits on the U.S.–Vietnam security relationship, including a Vietnamese defense establishment that is very cautious in its selection of defense partners, party-to-party ties between the Communist parties of Vietnam and China, and a foreign policy that seeks to balance relationships with all major powers. The U.S. remains, like others among Vietnam’s security partners, officially limited to one port call a year and has not docked a warship at Cam Ranh Bay since the end of the Vietnam War. This may change with the inauguration of a new international port there this year,33 but the benefits of that access will be shared among all capable Vietnamese partners, not just the U.S. Navy.

The U.S. and Malaysia have maintained a “steady level” of defense cooperation since the 1990s, despite occasional political differences. Each year, they now participate jointly in dozens of bilateral and multilateral exercises to promote effective cooperation across a range of missions.34 The U.S. has specifically discussed with Malaysia arrangements for rotating maritime patrol aircraft through Malaysian bases in Borneo.

The U.S.–Indonesia defense relationship revived in 2005 following a period of estrangement over American human rights concerns. It now includes regular joint exercises, port calls, and sale of weaponry. The U.S. is also working closely with Indonesia’s defense establishment to institute reforms in Indonesia’s strategic defense planning processes.

The U.S. is working across the board at modest levels of investment to help build Southeast Asia’s maritime security capacity.35 Most notable in this regard is the Maritime Security Initiative (MSI) announced by Secretary of Defense Ashton Carter in 2015.36

Afghanistan. On October 7, 2001, U.S. forces invaded Afghanistan in response to the September 11, 2001, attacks on the United States, marking the beginning of Operation Enduring Freedom to combat al-Qaeda and its Taliban supporters. The U.S., in alliance with the U.K. and the anti-Taliban Afghan Northern Alliance forces, ousted the Taliban from power in December 2001. Most Taliban and al-Qaeda leaders fled across the border into Pakistan’s Federally Administered Tribal Areas (FATA), where they regrouped and started an insurgency in Afghanistan in 2003.

In August 2003, NATO joined the war in Afghanistan and assumed control of the International Security Assistance Force (ISAF). At the height of the war in 2011, there were 50 troop-contributing nations and a total of nearly 150,000 NATO and U.S. forces on the ground in Afghanistan.

On December 28, 2014, NATO formally ended combat operations and handed responsibility to the Afghan security forces, currently numbering around 326,000 (including army and police).37 After Afghan President Ashraf Ghani signed a bilateral security agreement with the U.S. and a Status of Forces Agreement with NATO, the international coalition launched Operation Resolute Support to train and support Afghan security forces. As of June 2016, approximately 13,200 U.S. and NATO forces were stationed in Afghanistan. Most U.S. and NATO forces are stationed at bases in Kabul and Bagram, with tactical advise-and-assist teams located in Mazar-i-Sharif, Herat, Kandahar, Jalalabad, and Gamberi.

In 2014, President Obama pledged to cut U.S. force levels to around 5,500 by the end of 2015 and then to zero by the end of 2016, but he reversed himself last fall, announcing that the U.S. instead would maintain this force level when he departs office. He revised plans again in 2016 to say that he would keep 8,400 in place, leaving any further reductions up to his successor.

Pakistan. During the war in Afghanistan, the U.S. and NATO relied heavily on logistical supply lines running through Pakistan to resupply coalition forces in Afghanistan. Supplies and fuel were carried on transportation routes from the port at Karachi to Afghan–Pakistani border crossing points at Torkham in the Khyber Pass and Chaman in Baluchistan province. During the initial years of the Afghan war, about 80 percent of U.S. and NATO supplies traveled through Pakistani territory. This amount decreased to around 50 percent–60 percent as the U.S. shifted to northern routes and when U.S.–Pakistan relations significantly deteriorated over U.S. drone strikes, continued Pakistani support to Taliban militants, and the fallout surrounding the U.S. raid on Osama bin Laden’s hideout in Abbottabad on May 2, 2011.

From October 2001 until December 2011, the U.S. leased Pakistan’s Shamsi airfield southwest of Quetta in Pakistan’s Baluchistan province and used it as a base from which to conduct surveillance and drone operations against terrorist targets in Pakistan’s tribal border areas. Pakistan ordered the U.S. to vacate the base shortly after NATO forces attacked Pakistani positions along the Afghanistan border, killing 24 Pakistani soldiers, on November 26, 2011.

Escalation of the U.S. drone strike campaign in Pakistan’s border areas from 2009–2012 led to the significant degradation of al-Qaeda’s ability to plot, plan, and train for terrorist attacks. The U.S. began to curtail drone strikes in 2013, largely as a result of Pakistan’s growing complaints that the drone campaign infringed on its sovereignty and criticism from international human rights organizations about the number of civilian casualties resulting from the attacks. All told, there have been over 400 drone strikes since January 2008, including the strike that killed Taliban leader Mullah Akhtar Mansour in Baluchistan province in May 2016.

The U.S. provides significant amounts of military aid to Pakistan and “reimbursements” in the form of coalition support funds (CSF) for Pakistan’s military deployments and operations along the border with Afghanistan. Pakistan has some 150,000 troops stationed in regions bordering Afghanistan and recently conducted a robust military campaign against Pakistani militants in North Waziristan. Since FY 2002, the U.S. has provided almost $8 billion in security-related assistance and more than $14 billion in CSF funds to Pakistan.38 While $1 billion in CSF reimbursements was authorized for Pakistan in 2015, the U.S. withheld $300 million of this funding because of Pakistan’s failure to crack down on the Haqqani network. Reflecting a trend of growing congressional resistance to military assistance for Pakistan, in 2016, Congress blocked funds for the provision of eight F-16s to Pakistan.

India. During the Cold War, U.S.–Indian military cooperation was minimal, except for a brief period during the Sino–Indian border war in 1962 when the U.S. sided with India and supplied it with arms and ammunition. The rapprochement was short-lived, however, and mutual suspicion continued to mark the Indo–U.S. relationship due to India’s robust relationship with Russia and the U.S. provision of military aid to Pakistan, especially during the 1970s under the Nixon Administration. America’s ties with India hit a nadir during the 1971 Indo–Pakistani war when the U.S. deployed the aircraft carrier USS Enterprise toward the Bay of Bengal in a show of support for Pakistani forces.

Military ties between the U.S. and India have improved significantly over the past decade as the two sides have moved toward establishment of a strategic partnership based on their mutual concern over rising Chinese military and economic influence and converging interests in countering regional terrorism. The U.S. and India have completed contracts worth nearly $14 billion for the supply of U.S. military equipment to India, including C-130J and C-17 transport aircraft and P-8 maritime surveillance aircraft.

Defense ties between the two countries are poised to expand further as India moves forward with an ambitious military modernization program and following three successful summit-level meetings between President Obama and Indian Prime Minister Narendra Modi. During President Obama’s January 2015 visit to India, the two sides agreed to renew and upgrade their 10-year Defense Framework Agreement. Under the Defense Trade and Technology Initiative (DTTI) launched in 2012, the U.S. and India are cooperating on development of six very specific “pathfinder” technology projects.39 During Prime Minister Modi’s visit to the U.S. in June 2016, the two sides welcomed finalization of the text of a logistics-sharing agreement that would allow each country to access the other’s military supplies and refueling capabilities through ports and military bases. The signing of the logistics agreement, formally called the Logistics Exchange Memorandum of Agreement (LEMOA), marks a milestone in the Indo–U.S. defense partnership. New Delhi and Washington regularly hold joint exercises across all services, including an annual naval exercise in which Japan will now participate on an annual basis and in which Australia and Singapore have also participated in the past.

Quality of Allied Armed Forces in Asia

Because of the lack of an integrated, regional security architecture along the lines of NATO, the United States partners with most of the nations in the region on a bilateral basis. This means that there is no single standard to which all of the local militaries aspire; instead, there is a wide range of capabilities that are influenced by local threat perceptions, institutional interests, physical conditions, historical factors, and budgetary considerations. Moreover, the lack of recent major conflicts in the region makes assessing the quality of Asian armed forces difficult. Most Asian militaries have limited combat experience; some (e.g., Malaysia) have never fought an external war since gaining independence in the mid-20th century. The Indochina wars, the most recent high-intensity conflicts, are now 30 years in the past. It is therefore unclear how well Asian militaries have trained for future warfare and whether their doctrine will meet the exigencies of wartime realities. In particular, no Asian militaries have engaged in high-intensity air or naval combat, so the quality of their personnel, training, or equipment is likewise unclear.

Based on examinations of equipment, however, it is assessed that several Asian allies and friends have substantial military capabilities supported by robust defense industries and significant defense spending. Japan’s, South Korea’s, and Australia’s defense budgets are estimated to be among the 15 largest in the world. Each of their military forces fields some of the world’s most advanced weapons, including F-15s in the Japan Air Self Defense Force and ROK Air Force; airborne early warning (AEW) platforms; AEGIS-capable surface combatants and modern diesel-electric submarines; and third-generation main battle tanks. All three nations are currently committed to purchasing F-35 fighters.

At this point, both the Japanese and Korean militaries are arguably more capable than most European militaries, at least in terms of conventional forces. Japan’s Self Defense Forces, for example, field more tanks, principal surface combatants, and fighter/ground attack aircraft (777, 47, and 340, respectively) than their British opposite numbers (227, 18, and 230, respectively).40 Similarly, South Korea fields a larger military of tanks, principal surface combatants, submarines, and fighter/ground attack aircraft (more than 1,000, 28, 23, and 468, respectively) than their German counterparts (322, 19, four, and 209, respectively).41

Both the ROK and Japan are also increasingly interested in developing missile defense capabilities. Although South Korea and the United States agreed in 2016 (after much negotiation and indecision) to deploy America’s Terminal High-Altitude Area Defense (THAAD) missile defense system on the peninsula, South Korea also continues to pursue an indigenous missile defense capability.

Singapore’s small population and physical borders limit the size of its military and therefore its defense budget, but in terms of equipment and training, it nonetheless fields some of the highest-quality forces in the region. For example, Singapore’s ground forces can deploy third-generation Leopard II main battle tanks; its fleet includes five conventional submarines (including one with air-independent propulsion systems), six frigates, and six missile-armed corvettes; and the Singapore air force not only has F-15E Strike Eagles and F-16s, but also has one of Southeast Asia’s largest fleets of airborne early warning and control aircraft (six G550 aircraft) and a tanker fleet of KC-130s that can help extend range or time on station.

At the other extreme, the Armed Forces of the Philippines (AFP) are among the region’s weakest military forces. Having long focused on waging counterinsurgency campaigns while relying on the United States for its external security, the AFP has one of the lowest budgets in the region—and one of the most extensive coastlines to defend. With a defense budget of only $2.5 billion and confronted with a number of insurgencies, including the Islamist Abu Sayyaf and New People’s Army, Philippine defense resources have long been stretched thin. The last squadron of fighter aircraft (1960s-vintage F-5 fighters) was retired several years ago; the Philippine Air Force (PAF) has had to employ its S-211 trainers as fighters and ground attack aircraft. The most modern ships in the Philippine navy are two former U.S. Hamilton-class Coast Guard cutters; its other main combatant is a World War II destroyer escort, one of the world’s oldest serving warships.


Current U.S. Presence in Asia

The U.S. Pacific Command (PACOM) is the oldest and largest of American unified commands. Established on January 1, 1947, PACOM, “together with other U.S. government agencies, protects and defends the United States, its territories, allies, and interests”42 To this end, the U.S. seeks to preserve a “geographically distributed, operationally resilient, and politically sustainable” regional force posture within the PACOM area of responsibility that can effectively deter any potential adversaries.43

PACOM’s area of responsibility includes not only the expanses of the Pacific, but also Alaska and portions of the Arctic, South Asia, and the Indian Ocean. It includes 36 nations holding more than 50 percent of the world’s population, two of the three largest economies, and nine of the 10 smallest; the most populous nation (China); the largest democracy (India); the largest Muslim-majority nation (Indonesia); and the world’s smallest republic (Nauru). The region is a vital driver of the global economy and includes the world’s busiest international sea-lanes and nine of its 10 largest ports. By any meaningful measure, the Asia–Pacific is also the most militarized region in the world, with seven of its 10 largest standing militaries and five of its declared nuclear nations.44

Under PACOM are a number of component commands, including:

U.S. Army Pacific. USARPAC is the Army’s component command in the Pacific. It is comprised of 80,000 soldiers and supplies Army forces as necessary for various global contingencies. Among others, it administers the 25th Infantry Division headquartered in Hawaii, the U.S. Army Japan, and U.S. Army Alaska.45

U.S. Pacific Air Force. PACAF is responsible for planning and conducting defensive and offensive air operations in the Asia–Pacific region. It has three numbered air forces under its command: 5th Air Force (in Japan); 7th Air Force (in Korea); and 11th Air Force (headquartered in Alaska). These field two squadrons of F-15s, two squadrons of F-22s, five squadrons of F-16s, and a single squadron of A-10 ground attack aircraft, as well as two squadrons of E-3 early-warning aircraft, tankers, and transports.46 Other forces that regularly come under PACAF command include B-52, B-1, and B-2 bombers.

U.S. Pacific Fleet. PACFLT normally controls all U.S. naval forces committed to the Pacific, which usually represents 60 percent of the Navy’s fleet. It is organized into Seventh Fleet, headquartered in Japan, and Third Fleet, headquartered in California. Seventh Fleet comprises the forward-deployed element of PACFLT and includes the only American carrier strike group (CTF-70) and amphibious group (CTF-76) home-ported abroad, ported at Yokosuka and Sasebo, Japan, respectively. The Third Fleet’s area of responsibility (AOR) spans the West Coast of the United States to the International Date Line and includes the Alaskan coastline and parts of the Arctic. There is some discussion about whether to erase the western border of Third Fleet’s AOR47 to involve its five carrier strike groups48 more routinely in the Western Pacific.

Since the announcement of the “Asia pivot,” it has been reported that the United States will shift more Navy and Air Force assets to the Pacific. It is expected that eventually, some 60 percent of U.S. Navy assets will be deployed to the Pacific (although it remains unclear whether they will be permanently based there). That percentage, however, will be drawn from a fleet that is shrinking in overall size, so the net effect may actually be fewer forces deployed than before. Over the past year, the conduct of Freedom of Navigations Operations (FONOPS) that challenge excessive maritime claims, a part of the Navy’s mission since 1979, has assumed a very high profile as a result of three well-publicized operations in the South China Sea.

U.S. Marine Forces Pacific. MARFORPAC controls elements of the U.S. Marine Corps operating in the Asia–Pacific region. Its headquarters are in Hawaii. Because of its extensive responsibilities and physical span, MARFORPAC controls two-thirds of Marine Corps forces: the I Marine Expeditionary Force (MEF), centered on the 1st Marine Division, 3rd Marine Air Wing, and 1st Marine Logistics Group, and the III Marine Expeditionary Force, centered on the 3rd Marine Division, 1st Marine Air Wing, and 3rd Marine Logistics Group.49 The I MEF is headquartered at Camp Pendleton, California, and the III MEF is headquartered on Okinawa, although each has various subordinate elements deployed at any time throughout the Pacific on exercises, maintaining presence, or engaged in other activities. MARFORPAC is responsible for supporting three different commands: It is the U.S. Marine Corps component to PACOM, provides the Fleet Marine Forces to PACFLT, and provides Marine forces for U.S. Forces Korea (USFK).50

U.S. Special Operations Command Pacific. SOCPAC has operational control of various special operations forces, including Navy SEALs; Naval Special Warfare units; Army Special Forces (Green Berets); and Special Operations Aviation units in the Pacific region, including elements in Japan and South Korea. It supports the Pacific Command’s Theater Security Cooperation Program as well as other plans and contingency responses. Until 2015, this included Joint Special Operations Task Force–Philippines (JSOTF-P), 500–600 soldiers assisting Manila in combatting Islamist insurgencies in the southern Philippines such as Abu Sayyaf. SOCPAC forces also support various operations in the region other than warfighting, such as counterdrug operations, counterterrorism training, humanitarian assistance, and de-mining activities.

U.S. Forces Korea and U.S. Eighth Army. Because of the unique situation on the Korean peninsula, two subcomponents of PACOM, U.S. Forces Korea (USFK) and U.S. Eighth Army, are based in Korea. USFK, a joint headquarters led by a four-star U.S. general, is in charge of the various U.S. military elements on the Korean peninsula. U.S. Eighth Army operates in conjunction with USFK as well as with the United Nations presence in the form of United Nations Command.

Other forces, including space capabilities, cyber capabilities, air and sealift assets, and additional combat forces, may be made available to PACOM depending on requirements and availability.

U.S. Central Command—Afghanistan. Unlike the U.S. forces deployed in Japan and South Korea, there is not a permanent force structure committed to Afghanistan; instead, forces rotate through the theater under the direction of PACOM’s counterpart in that region of the world, U.S. Central Command (CENTCOM). As of May 2016, these forces included:

  • Resolute Support Mission, including U.S. Forces Afghanistan.51
  • Special Operations Joint Task Force—Afghanistan. This includes a Special Forces battalion, based out of Bagram Airfield, and additional allied special operations forces at Kabul.
  • 9th Air and Space Expeditionary Task Force. This includes the 155th Air Expeditionary Wing, providing air support from Bagram airfield; the 451st Air Expeditionary Group and 455th Expeditionary Operations Group, operating from Kandahar and Bagram airfields, respectively, providing air support and surveillance operations over various parts of Afghanistan; and the 421st Expeditionary Fighter Squadron, providing close air support from Bagram airfield.
  • Combined Joint Task Force 10/10th Mountain Division, centered on Bagram airfield. This is the main U.S. national support element. It includes seven battalions of infantry, air defense artillery for counter-artillery missions, and explosive ordnance disposal across Afghanistan. It also includes three Army aviation battalions, a combat aviation brigade headquarters, and two additional joint task forces to provide nationwide surveillance support.52
  • Five Train, Advise, Assist Commands in Afghanistan, each of which is a multinational force tasked with improving local capabilities to conduct operations.53

Key Infrastructure That Enables Expeditionary Warfighting Capabilities

Any planning for operations in the Pacific will be dominated by the “tyranny of distance.” Because of the extensive distances that must be traversed in order to deploy forces, even Air Force units will take one or more days to deploy, while ships measure steaming time in weeks. For instance, a ship sailing at 20 knots requires nearly five days to get from San Diego to Hawaii. From there, it takes a further seven days to get to Guam, seven days to Yokosuka, Japan, and eight days to Okinawa—if ships encounter no interference along the journey.54

China’s growing anti-access/area denial (A2/AD) capabilities, ranging from an expanding fleet of modern submarines to anti-ship ballistic and cruise missiles, increase the operational risk for deployment of U.S. forces in the event of conflict. China’s capabilities not only jeopardize American combat forces that would flow into the theater for initial combat, but also would continue to threaten the logistical support needed to sustain American combat power for the subsequent days, weeks, and months.

American basing structure in the Indo–Pacific region, including access to key allied facilities, is therefore both necessary and increasingly at risk.

American Facilities

Much as in the 20th century, Hawaii remains the linchpin of America’s ability to support its position in the Western Pacific. If the United States cannot preserve its facilities in Hawaii, then both combat power and sustainability become moot. The United States maintains air and naval bases, communications infrastructure, and logistical support on Oahu and elsewhere in the Hawaiian Islands. Hawaii is also a key site for undersea cables that carry much of the world’s communications and data, as well as satellite ground stations.

The American territory of Guam is located 4,600 miles farther west. Obtained from Spain as a result of the Spanish–American War, Guam became a key coaling station for U.S. Navy ships. Seized by Japan in World War II, it was liberated by U.S. forces in 1944 and after the war became an unincorporated, organized territory of the United States. Key U.S. military facilities on Guam include U.S. Naval Base Guam, which houses several attack submarines and may add an aircraft carrier berth, and Andersen Air Force Base, one of a handful of facilities that can house B-2 bombers. U.S. task forces, meanwhile, can stage out of Apra Harbor, drawing weapons from the Ordnance Annex in the island’s South Central Highlands. There is also a communications and data relay facility on the island.

Over the past 20 years, Guam’s facilities have steadily improved. B-2 bombers, for example, began operating from Andersen Air Force Base in 2005.55 These improvements have been accelerated and expanded even as China’s A2/AD capabilities have raised doubts about the ability to sustain operations in the Asian littoral. The concentration of air and naval assets as well as logistical infrastructure, however, makes the island an attractive potential target in the event of conflict.

The U.S. military has non-combatant maritime prepositioning ships (MPS), which contain large amounts of military equipment and supplies, in strategic locations from which they can reach areas of conflict relatively quickly as associated U.S. Army or Marine Corps units located elsewhere arrive in the areas. The U.S. Navy has units on Guam and in Saipan, Commonwealth of the Northern Marianas, which support prepositioning ships that can supply Army or Marine Corps units deployed for contingency operations in Asia.

Allied and Friendly Facilities

For the United States, access to bases in Asia has long been a prerequisite for supporting any American military operations in the region. Even with the extensive aerial refueling and underway replenishment skills of the U.S. Air Force and U.S. Navy, it is still essential for the United States to retain access to resupply and replenishment facilities, at least in peacetime. The ability of those facilities not only to survive, but also to function will directly influence the course of any conflict in the Western Pacific region. Moreover, a variety of support functions, including communications, intelligence, and space support, cannot be accomplished without facilities in the region.

At the present time, it would be extraordinarily difficult to maintain maritime domain awareness or space situational awareness without access to facilities in the Asia–Pacific region. The American alliance network, outlined previously, is therefore a matter both of political partnership and also of access to key facilities on allied soil.

Japan. In Japan, the United States has access to over 100 different facilities, including communications stations, military and dependent housing, fuel and ammunition depots, and weapons and training ranges. This access comes in addition to major bases such as air bases at Misawa, Yokota, and Kadena and naval facilities at Yokosuka, Atsugi, and Sasebo. The naval facilities support the USS Ronald Reagan carrier strike group (CSG), which is home-ported in Yokosuka, as well as a Marine Expeditionary Strike Group (ESG) centered on the USS Bonhomme Richard, home-ported at Sasebo. Additionally, the skilled work force at places like Yokosuka is an integral part of maintaining American forces and repairing equipment in time of conflict. Replacing them would take years. This combination of facilities and work force, in addition to physical location and political support, makes Japan an essential part of any American military response to contingencies in the Western Pacific. Japanese financial support for the American presence also makes these facilities some of the most cost-effective in the world.

The status of one critical U.S. base has been a matter of public debate in Japan for many years. The U.S. Marine Corps’ Third Marine Expeditionary Force, based on Okinawa, is the U.S.’s rapid reaction force in the Pacific. The Marine Air-Ground Task Force, comprised of air, ground, and logistics elements, enables quick and effective response to crisis or humanitarian disasters. In response to local protests, the Marines are reducing their footprint by relocating some units to Guam as well as to less-populated areas of Okinawa. The latter includes moving a helicopter unit from Futenma to a new facility in a more remote location in northeastern Okinawa. Because of local resistance, construction of the Futenma Replacement Facility at Camp Schwab will not be complete until 2025, but the U.S. and Japanese governments have affirmed their support for the project.

South Korea. The United States also maintains an array of facilities in South Korea, with a larger Army footprint than in Japan, as the United States and South Korea remain focused on deterring North Korean aggression and preparing for any possible North Korean contingencies. The Army maintains four major facilities (which in turn control a number of smaller sites) at Daegu, Yongsan in Seoul, and Camps Red Cloud/Casey and Humphreys. These facilities support the U.S. 2nd Infantry Division, which is based in South Korea. Other key facilities include air bases at Osan and Kunsan as well as a naval facility at Chinhae near Pusan.

The Philippines. In 1992, The United States ended nearly a century-long presence in the Philippines when it withdrew from its base in Subic Bay as its lease there ended. Clark Air Base had been closed earlier due to the eruption of Mount Pinatubo; the costs of repairing the facility were deemed too high to be worthwhile. In 2014, however, with the growing Chinese assertiveness in the South China Sea, including against Philippine claims such as Mischief Reef and Scarborough Shoal, the U.S. and the Philippines negotiated the EDCA, which will allow for the rotation of American forces through Philippine military bases.

In 2016, the two sides agreed on an initial list of five bases in the Philippines that will be involved. Geographically distributed across the country, they are Antonio Bautista Air Base (in Palawaan closest to the Spratlys); Basa Air Base (on the main island of Luzon and closest to the hotly contested Scarborough Shoal); Fort Magsaysay (also on Luzon and the only facility on the list that is not an air base); Lumbia Air Base (in Mindanao where Manila remains in low-intensity combat with Islamist insurgents); and Mactan-Benito Ebuen Air Base (central Philippines).56

It remains unclear precisely which forces would be rotated through the Philippines as a part of this agreement, which in turn affects the kinds of facilities that would be most needed. However, outside the context of the EDCA, the U.S. deployed E/A-18G Growler electronic attack, A-10 Warthog close air support aircraft, and Pavehawk helicopters to the Philippines in 2016.57 The base upgrades and deployments pursuant to the EDCA are part of a broader expansion of U.S.–Philippine defense ties, which most recently included the U.S. leaving behind men and matériel at Clark Air Base following annual exercises,58 as well as joint naval patrols and increased levels of assistance under the Maritime Security Initiative (MSI). The Philippines is receiving the bulk of assistance in the first year of this five-year $425 million program.

Singapore. The United States does not have bases in Singapore but is allowed access to several key facilities that are essential for supporting American forward presence. Since the closure of its facilities at Subic Bay, the United States has been allowed to operate the principal logistics command for the Seventh Fleet out of the Port of Singapore Authority’s (PSA) Sembawang Terminal. The U.S. Navy also has access to Changi Naval Base, one of the few docks in the world that can handle a 100,000-ton American aircraft carrier. In addition, a small U.S. Air Force contingent operates out of Paya Lebar Air Base to support U.S. Air Force combat units visiting Singapore and Southeast Asia, and Singapore hosts two new Littoral Combat Ships (LCS) (with the option of hosting two more) and a rotating squadron of F-16 fighter aircraft.59

Australia. A much-discussed element of the “Asia pivot” has been the 2011 agreement to deploy U.S. Marines to Darwin in northern Australia. While planned to amount to 2,500 Marines, the rotations fluctuate and have not yet reached that number. “In its mature state, the Marine Rotational Force–Darwin (MRF-D) will be a Marine Air-Ground Task Force…with a variety of aircraft, vehicles and equipment.”60 The Marines do not constitute a permanent presence in Australia, in keeping with Australian sensitivities about permanent American bases on Australian soil.61 Similarly, the United States jointly staffs the Joint Defence Facility Pine Gap and the Joint Geological and Geophysical Research Station at Alice Springs and has access to the Harold E. Holt Naval Communication Station in Western Australia, including the space surveillance radar system there.62

Finally, the United States is granted access to a number of facilities in Asian states on a contingency or crisis basis. Thus, U.S. Air Force units transited Thailand’s U-Tapao Air Base and Sattahip Naval Base during the first Gulf War and in the Iraq War, but they do not maintain a permanent presence there. Additionally, the U.S. Navy conducts hundreds of port calls throughout the region.

Diego Garcia. Essential to U.S. operations in the Indian Ocean and Afghanistan and providing essential support to both the Middle East and East Asia are the American facilities on the British territory of Diego Garcia. The island is home to the 12 ships of Maritime Prepositioning Squadron (MPS)-2, which can support a Marine brigade and associated Navy elements for 30 days. There are also several elements of the U.S. global space surveillance and communications infrastructure on the island, as well as basing facilities for the B-2 bomber.


The Asian strategic environment is extremely expansive, as it spans half the globe, with a variety of political relationships among states that have wildly varying capabilities. The region includes long-standing American allies with relationships dating back to the beginning of the Cold War as well as recently established states and some long-standing adversaries such as North Korea.

American conceptions of the region must therefore start from the physical limitations imposed by the tyranny of distance. Moving forces within the region, never mind to it, will take time and require extensive strategic lift assets as well as sufficient infrastructure (such as sea and aerial ports of debarkation that can handle American strategic lift assets) and political support. At the same time, the complicated nature of intra-Asian relations, especially unresolved historical and territorial issues, means that, unlike Europe, the United States cannot necessarily count on support from all of its regional allies in event of any given contingency.

Scoring the Asia Operating Environment

As with the operating environments of Europe and the Middle East, we assessed the characteristics of Asia as they would pertain to supporting U.S. military operations. Various aspects of the region facilitate or inhibit America’s ability to conduct military operations to defend its vital national interests against threats. Our assessment of the operating environment utilized a five-point scale, ranging from “very poor” to “excellent” conditions and covering four regional characteristics of greatest relevance to the conduct of military operations:

  1. Very Poor. Significant hurdles exist for military operations. Physical infrastructure is insufficient or nonexistent, and the region is politically unstable. The U.S. military is poorly placed or absent, and alliances are nonexistent or diffuse.
  2. Unfavorable. A challenging operating environment for military operations is marked by inadequate infrastructure, weak alliances, and recurring political instability. The U.S. military is inadequately placed in the region.
  3. Moderate. A neutral to moderately favorable operating environment is characterized by adequate infrastructure, a moderate alliance structure, and acceptable levels of regional political stability. The U.S. military is adequately placed.
  4. Favorable. A favorable operating environment includes good infrastructure, strong alliances, and a stable political environment. The U.S. military is well placed in the region for future operations.
  5. Excellent. An extremely favorable operating environment includes well-established and well-maintained infrastructure, strong capable allies, and a stable political environment. The U.S. military is exceptionally well placed to defend U.S. interests.

The key regional characteristics consisted of:

a. Alliances. Alliances are important for interoperability and collective defense as allies would be more likely to lend support to U.S. military operations. Various indicators provide insight into the strength or health of an alliance. These include whether the U.S. trains regularly with countries in the region, has good interoperability with the forces of an ally, and shares intelligence with nations in the region.

b. Political Stability. Political stability brings predictability for military planners when considering such things as transit, basing, and overflight rights for U.S. military operations. The overall degree of political stability indicates whether U.S. military actions would be hindered or enabled and considers, for example, whether transfers of power in the region are generally peaceful and whether there have been any recent instances of political instability in the region.

c. U.S. Military Positioning. Having military forces based or equipment and supplies staged in a region greatly facilitates the ability of the United States to respond to crises and, presumably, more quickly achieve successes in critical “first battles.” Being routinely present in a region also assists in maintaining familiarity with its characteristics and the various actors who might act to assist or thwart U.S. actions. With this in mind, we assessed whether or not the U.S. military was well-positioned in the region. Again, indicators included bases, troop presence, prepositioned equipment, and recent examples of military operations (including training and humanitarian) launched from the region.

d. Infrastructure. Modern, reliable, and suitable infrastructure is essential to military operations. Airfields, ports, rail lines, canals, and paved roads enable the U.S. to stage, launch operations from, and logistically sustain combat operations. We combined expert knowledge of regions with publicly available information on critical infrastructure to arrive at our overall assessment of this metric.63

For Asia, we arrived at these average scores:

  • Alliances: 5—Excellent
  • Political Stability: 4—Favorable
  • U.S. Military Positioning: 4—Favorable
  • Infrastructure: 4—Favorable

Aggregating to a regional score of: Favorable


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(accessed September 17, 2014). 

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  3. Ministry of Foreign Affairs of Japan, “Japan’s Policies on the Control of Arms Exports,” (accessed September 17, 2014). 

  4. U.S. Forces, Japan, “About USFJ,” (accessed April 12, 2016). 

  5. Emma Chanlett-Avery, William H. Cooper, Mark E. Manyin, and Ian E. Rinehart, “Japan–U.S. Relations: Issues for Congress,” Congressional Research Service Report for Members and Committees of Congress, February 20, 2014, (accessed August 25, 2016). 

  6. Chang Jae-soon, “U.S., Japan Announces [sic] New Defense Cooperation Guidelines,” Yonhap News Agency, April 28, 2015, (accessed May 21, 2015). 

  7. K. J. Kwon, “South Korea and Japan Put Military Intelligence Pact on Hold After Outcry,” CNN, June 29, 2012, (accessed September 17, 2014). 

  8. Martin Fackler and David E. Sanger, “Japan Announces a Military Shift to Thwart China,” The New York Times, July 1, 2014, (accessed August 25, 2016). 

  9. For further details, see Bruce Klingner, “The U.S. and South Korea Should Focus on Improving Alliance Capabilities Rather Than the OPCON Transfer,” Heritage Foundation Backgrounder No. 2935, August 7, 2014, 

  10. U.S. Department of Defense, Inspector General, Host Nation Support of U.S. Forces in Korea, Report No. D-2008-118, August 2008, (accessed August 25, 2016). 

  11. Gina Harkins, “The New Look for U.S.–Philippine Military Relations,” Marine Corps Times, April 26, 2015, (accessed July 25, 2016). 

  12. “Fact Sheet: United States–Philippines Bilateral Relations,” The White House, April 28, 2014, 
(accessed November 15, 2014). 

  13. Ben Dolven, Shirley A. Kan, and Mark E. Manyin, “Maritime Territorial Disputes in East Asia: Issues for Congress,” Congressional Research Service Report for Congress, January 30, 2013, pp. 28–29, (accessed August 25, 2016). 

  14. Walter Lohman, “Scarborough Shoal and Safeguarding American Interests,” Heritage Foundation Issue Brief No. 3603, 
May 14, 2012, 

  15. Emma Chanlett-Avery, Ben Dolven, and Wil Mackey, “Thailand: Background and U.S. Relations,” Congressional Research Service Report for Members and Committees of Congress, July 29, 2015, pp. 8–9, 
(accessed August 25, 2016). 

  16. U.S. Central Intelligence Agency, The World Factbook, “East & Southeast Asia: Thailand,” last updated August 15, 2016, (accessed August 25, 2016). 

  17. Phuong Nguyen and Brittany Billingsley, “China’s Growing Military-to-Military Engagement with Thailand & Myanmar,” Center for Strategic and International Studies, Asia Program, September 12, 2013, (accessed September 17, 2014). 

  18. Australian Government, Department of Defence, “United States Force Posture Initiatives in Australia,” (accessed August 25, 2016). 

  19. Matthew L. Schehl, “U.S., Australia, Delay Plans to Send More Marines Down Under,” Marine Corps Times, June 16, 2016, (accessed July 26, 2016). 

  20. Aaron Mehta, “US, UK, Australia and Canada Announce Combined Space Ops,” vBulletin, May 20, 2014, (accessed August 29, 2016). 

  21. Bruce Vaugh, “Australia: Background and U.S. Relations,” Congressional Research Service Report for Congress, August 15, 2013, pp. 4–5, (accessed September 17, 2014). 

  22. Minister for Defence Stephen Smith, “Ministerial Statement on Full Knowledge and Concurrence,” Australian Government, Department of Defence Ministers, June 26, 2013, (accessed September 17, 2014). 

  23. “Fact Sheet: U.S. Defense Trade Cooperation Treaties with the United Kingdom and Australia,” U.S. Department of State, September 30, 2010, (accessed August 25, 2016). 

  24. Emma Chanlett-Avery, “Singapore: Background and U.S. Relations,” Congressional Research Service Report for Congress, 
July 26, 2013, pp. 3–4, (accessed May 15, 2015). 

  25. Ibid. 

  26. U.S. Department of Defense, “Carter, Singapore Defense Minister Sign Enhanced Defense Cooperation Agreement,” DoD News, December 7, 2015, (accessed July 26, 2016). 

  27. Nick Simeone, “U.S., New Zealand Announce Expanded Defense Cooperation,” American Forces Press Service, October 28, 2013, (accessed August 25, 2016). 

  28. David Larter, “In Port Visit, New Zealand and U.S. Seek to Bolster Military Ties,” Navy Times, July 22, 2016, (accessed August 18, 2016). 

  29. Taiwan Relations Act, Public Law 96-8, 22 U.S.C. §§ 3301–3316. 

  30. Ibid. 

  31. Shirley A. Kan, “China/Taiwan: Evolution of the ‘One China’ Policy—Key Statements from Washington, Beijing, and Taipei,” Congressional Research Service Report for Members and Committees of Congress, October 10, 2014, (accessed September 21, 2015). 

  32. U.S. Pacific Command, “Joint Statement: Between the United States of America and the Socialist Republic of Vietnam,” 
May 23, 2016, (accessed August 27, 2016). 

  33. Prashanth Parameswaran, “Vietnam Unveils New Port Facility for Foreign Warships in Cam Ranh Bay,” The Diplomat, 
March 10, 2016, (accessed July 26, 2016). 

  34. Ian E. Rinehart, “Malaysia: Background and U.S. Relations,” Congressional Research Service Report for Members and Committees of Congress, November 19, 2015, (accessed August 27, 2016). 

  35. “FACT SHEET: U.S. Building Maritime Capacity in Southeast Asia,” The White House, November 17, 2015, 
(accessed July 27, 2016). 

  36. Prashanth Parameswaran, “US Kicks Off New Maritime Security Initiative for Southeast Asia,” The Diplomat, April 10, 2016, (accessed August 26, 2016). 

  37. Josh Smith, “Casualties, Desertions Spike as Afghan Forces Take the Lead,” Stars and Stripes, March 4, 2015, 
(accessed August 27, 2016). 

  38. Congressional Research Service, “Direct Overt U.S. Aid Appropriations for and Military Reimbursements to Pakistan, FY2002–FY2017,” February 24, 2016, (accessed August 27, 2016). 

  39. Press Trust of India, “Ind[ia], US Agree on 2 New Pathfinder Projects,” India Today, April 12, 2016, (accessed August 27, 2016). 

  40. International Institute for Strategic Studies, The Military Balance 2015: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2015), pp. 186–191 and 306–309. 

  41. Ibid., pp. 137–140 and 312–315. 

  42. Donna Miles, “Pacom: Asia–Pacific Focus Represents ‘Whole of Government’ Rebalance,” American Forces Press Service, 
August 3, 2012, (accessed August 27, 2016). 

  43. U.S. Department of State, “Joint Statement of the Security Consultative Committee,” April 26, 2012, (accessed September 17, 2014). 

  44. U.S. Pacific Command, “USPACOM Strategy,” (accessed August 27, 2016). 

  45. United States Army Pacific, “About USARPAC,” (accessed July 27, 2016). 

  46. International Institute for Strategic Studies, The Military Balance 2016: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2016), p. 46. 

  47. Tim Kelly, “U.S. Admiral Signals Wider Role for Powerful Third Fleet in Western Pacific,” Reuters, September 26, 2015, (accessed July 27, 2016). 

  48. Commander, U.S. Third Fleet, “Third Fleet: Who We Are, What We Do, Why We Do It,” 
(accessed July 27, 2016). 

  49. U.S. Marine Corps, “U.S. Marine Corps Forces, Pacific (MARFORPAC),” last revised March 10, 2015, (accessed August 27, 2016). 

  50. Ibid. 

  51. Wesley Morgan, “Afghanistan Order of Battle: Coalition Combat and Advisory Forces in Afghanistan,” Institute for the Study of War, May 1, 2016, p. 1, (accessed July 6, 2016). 

  52. Ibid. 

  53. United States Central Command, “Resolute Support,” (accessed July 6, 2016). 

  54. These steaming times were calculated using Marine Vessel Traffic, “Sea Distance Calculator,” 2016, (accessed August 27, 2016). 

  55. Airforce Technology, “B-2 Spirit Stealth Bomber, United States of America,”
(accessed August 23, 2016). 

  56. News release, “Sixth United States–Philippines Bilateral Strategic Dialogue Joint Statement,” U.S. Department of State, 
March 18, 2016, (accessed July 27, 2016). 

  57. Phillip Swarts, “Navy Growlers Replace A-10s, Pavehawks in Philippine Rotation,” Air Force Times, July 4, 2016,–10s-pavehawks-philippine-rotation/86480124/ (accessed August 27, 2016). 

  58. Eric Haun, “US Ramps up Military Presence in the Philippines,” Marine Link, April 14, 2016, (accessed July 27, 2016). 

  59. Sam LaGrone, “Two Littoral Combat Ships to Deploy to Singapore Next Year, Four by 2017,” USNI News, April 24, 2015, 
(accessed August 23, 2016). 

  60. Australian Government, Department of Defence, “United States Force Posture Initiatives in Australia.” 

  61. Wyatt Olson, “Deal to Bring More US Assets to Australia,” Stars and Stripes, June 21, 2014, 
(accessed August 23, 2016). 

  62. Smith, “Ministerial Statement on Full Knowledge and Concurrence.” 

  63. For an example of a very accessible database, see World Bank, “Logistics Performance Index: Quality of Trade and Transport-Related Infrastructure (1=Low to 5=High),” (accessed August 26, 2016).