The United States is a global power with global interests. Scaling its military power to threats requires judgments with regard to the importance and priority of those interests, whether the use of force is the most appropriate and effective means of addressing the threats to them, and how much and what types of force are needed to defeat such threats.

This Index focuses on three fundamental, vital national interests:

  • Defense of the homeland;
  • Successful conclusion of a major war having the potential to destabilize a region of critical interest to the U.S.; and
  • Preservation of freedom of movement within the global commons: the sea, air, and outer space domains through which the world conducts business.

The geographical focus of the threats in these areas is further divided into three broad regions: Asia, Europe, and the Middle East.

This is not to say that these are America’s only interests. Among many others, the U.S. has an interest in the growth of economic freedom in trade and investment, the observance of internationally recognized human rights, and the alleviation of human suffering beyond our borders. None of these interests, however, can be addressed principally and effectively by the use of military force, nor would threats to these interests result in material damage to the foregoing vital national interests. These additional American interests, however important they may be, therefore will not be used in this assessment of the adequacy of current U.S. military power.

We reference two public sources throughout the document as a mechanism to check our work against that of other recognized professional organizations in the field of threat analysis: the International Institute for Strategic Studies’ annual The Military Balance1and the annual Worldwide Threat Assessment of the US Intelligence Community (WWTA).2 The latter serves as a reference point produced by the U.S. government against which each threat assessment in this Index was compared. We note any differences between assessments in this Index and the work of the two primary references in summary comments.

The juxtaposition of our detailed, reviewed analysis against both The Military Balance and the WWTA revealed two stark limitations in these external sources. First, The Military Balance is an excellent, widely consulted source, but it is only a count of military hardware without context in terms of equipment capability, maintenance and readiness, training, manpower, integration of services, and doctrine. Second, the WWTA omits many threats and is bare in its analysis of those it does address. Moreover, it does not reference underlying strategic dynamics that are key to the evaluation of threats and that may be more predictive of future threats than a simple extrapolation of current events.

We suspect this is a consequence of the U.S. intelligence community’s withholding its very sensitive assessments derived from classified sources from public view. While such a policy is quite understandable given the need to avoid compromising sources and methods of collection, it does mean that the WWTA’s views on threats are of limited value to policymakers, the public, and analysts working outside of the government. Surprisingly, The Heritage Foundation’s Index of U.S. Military Strength may actually serve as a useful correction to the systemic deficiencies we found in these open sources.

Measuring or categorizing a threat is problematic since there is no absolute reference that assists in assigning a quantitative score. There are two fundamental aspects of threats that are germane to this Index: the desire or intent of the threatening entity to achieve their objective and their physical ability to do so. Physical ability is the easier of the two to assess while intent is quite hard. A useful surrogate for intent is observed behavior since this is where we see intent become manifest through action. Thus, a provocative, belligerent pattern of behavior that seriously threatens U.S. vital interests would be very worrisome. Similarly, a comprehensive ability to accomplish objectives even in the face of U.S. military power would cause serious concern for U.S. policymakers while weak or very limited abilities would lessen U.S. concerns even if an entity behaved provocatively vis-à-vis U.S. interests. Each categorization used is meant to convey a word picture of how troubling a threat’s behavior and set of capabilities has been during the assessed year.

The five ascending categories for observed behavior are:

  • benign,
  • assertive,
  • testing,
  • aggressive, and
  • hostile

The five ascending categories for physical capability are:

  • marginal,
  • aspirational,
  • capable,
  • gathering, and
  • formidable

These characterizations—behavior and capability—form two halves of an overall assessment of threats to U.S. vital interests.

As noted, the following assessments are arranged by region (Europe, Middle East, and Asia) to correspond with the flow of the chapter on operating environments and then by U.S. vital interest (threat posed by an actor to the U.S. homeland, potential for regional war, and freedom of global commons) within each region. Each actor is then discussed in terms of how and to what extent its behavior and physical capabilities have posed a challenge to U.S. interests in the assessed year.

Threat scale by behavioral and capability standards


  1. International Institute for Strategic Studies, The Military Balance 2014 (London: Routledge, 2014).  

  2. James R. Clapper, Director of National Intelligence, “Statement for the Record: Worldwide Threat Assessment of the US Intelligence Community, Senate Select Committee on Intelligence,” January 29, 2014.