The United States is a global power with global interests. Scaling its military power to threats requires careful judgments with regard to the importance and priority of those interests, whether the use of force is the most appropriate and effective way to address the threats to those interests, 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 that has 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 nations of the world conduct their 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. Thus, these additional American interests, however important they may be, are not used in this assessment of the adequacy of current U.S. military power.
In previous editions of this Index, we referenced two public sources as a mechanism with which to check our work against that of other recognized professional organizations in the field of threat analysis: The Military Balance, published annually by the London-based International Institute for Strategic Studies,1 and the annual Worldwide Threat Assessment of the US Intelligence Community (WWTA).2 The latter served as a reference point produced by the U.S. government against which each threat assessment in this Index was compared. We noted 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.
- The Military Balance is an excellent and widely consulted source, but it is only a count of military hardware and lacks context in terms of equipment capability, maintenance and readiness, training, manpower, integration of services, doctrine, or the behavior of competitors that threaten the national interests of the U.S. as defined in this Index.
- The WWTA omits many threats, and its analysis of those that it does address is limited. 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 is a simple extrapolation of current events.
With respect to the WWTA, its limitations are most likely caused by the withholding from public view of the intelligence community’s very sensitive assessments, which are derived from classified sources and/or result from analysis of unclassified, publicly available documents, with the resulting synthesized insights becoming classified by virtue of what they reveal about U.S. determinations and concerns. Given the need to avoid compromising sources, methods of collection, and national security findings, such a policy is understandable, but it also causes the WWTA’s threat assessments to be of limited value to policymakers, the public, and analysts working outside of the government. We have therefore decided to stop using the WWTA as a reference and trust that the reader will double-check our conclusions with the various sources cited in the following pages as well as other publicly available reporting on challenges to core U.S. security interests discussed in this section.
Measuring or categorizing a threat is problematic because there is no absolute reference that can be used in assigning a quantitative score. Two fundamental aspects of threats, however, are germane to this Index: the threatening entity’s desire or intent to achieve its objective and its physical ability to do so. Physical ability is the easier of the two to assess; intent is quite difficult. A useful surrogate for intent is observed behavior, because this is where intent becomes 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 in the Index conveys a word picture of how troubling a threat’s behavior and set of capabilities have been during the assessed year. The five ascending categories for observed behavior are:
- Aggressive, and
The five ascending categories for physical capability are:
- Gathering, and
These characterizations—behavior and capability—form two halves of an overall assessment of the threats to U.S. vital interests.
In another significant departure from previous editions, we have changed the organizational structure from a U.S. interests–based approach, by region, to one that focuses squarely on threat actors. In our previous approach, the reader would see China assessed in each section per U.S. interest: threats to the U.S. homeland, threats to regional stability, and threats to free movement in the commons. This seemed confusing, so in this edition, the reader will see China addressed once, with discussion of how it challenges U.S. interests. The same approach is used to discuss Russia, Iran, North Korea, and relevant terrorist groups.
We always hold open the potential to add or delete from this list of threat actors; inclusion of any state or non-state entity is based solely on our assessment of its ability to pose a meaningful challenge to a critical U.S. interest.
- International Institute for Strategic Studies, The Military Balance 2014: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2014); The Military Balance 2015: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2015); The Military Balance 2016: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2016); The Military Balance 2017: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2017); and The Military Balance 2018: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2018).
- James R. Clapper, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Select Committee on Intelligence, U.S. Senate, January 29, 2014, http://www.dni.gov/files/documents/Intelligence%20Reports/2014%20WWTA%20%20SFR_SSCI_29_Jan.pdf; James R. Clapper, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Committee on Armed Services, U.S. Senate, February 26, 2015, http://www.armed-services.senate.gov/imo/media/doc/Clapper_02-26-15.pdf; James R. Clapper, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Committee on Armed Services, U.S. Senate, February 9, 2016, https://www.armed-services.senate.gov/imo/media/doc/Clapper_02-09-16.pdf; Daniel R. Coats, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Select Committee on Intelligence, U.S. Senate, May 11, 2017, https://www.dni.gov/files/documents/Newsroom/Testimonies/SSCI%20Unclassified%20SFR%20-%20Final.pdf; and Daniel R. Coats, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Select Committee on Intelligence, U.S. Senate, February 13, 2018, https://www.dni.gov/files/documents/Newsroom/Testimonies/2018-ATA---Unclassified-SSCI.pdf.