Assessing U.S. Vital National Security Interests

The United States is a global power, but one that must make judgments about the importance and priority of its global 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 overcome such threats.

This Index focuses on three fundamental, vital national interests:

1. Defense of the homeland;
2. Successful conclusion of a major war; and
3. Preservation of freedom of movement across free and open air and maritime lanes.

The geographical focus of the threats in these areas is further divided into five broad regions: Western Hemisphere/Latin America, Asia, Europe, the Middle East, and Africa.

Measuring or categorizing a threat is challenging because there are no absolute references that can be quantified. Two fundamental aspects of threats, however, are pertinent to the 2026 Index: the threatening entity’s intent and its capability to achieve that intent. While capability is the easier of the two factors to assess, intent can at times be difficult. What policymakers and defense planners can and should do, however, is listen to the words our adversaries use and observe their subsequent behavior. In this sense, a pattern of coercive language backed by military capability and real-world application of force would indicate that our adversaries seek to threaten U.S. vital interests either directly or indirectly. The United States is fortunate in its enemies: China, Russia, Iran, and North Korea have been very forthcoming in their intentions—and have exhibited behaviors and fielded capabilities that lend credence to such intentions.

Any single actor that threatened U.S. vital interests, particularly in the face of U.S. military power, would be of concern to U.S. policymakers. If that actor had both the capability and the intent or behavior to do so, this would obviously be a major concern.

Each categorization used in the 2026 Index conveys a picture of an adversary’s behavior and military capabilities. The five ascending categories for adversary behavior are:

• Benign,
• Assertive,
• Testing,
• Aggressive, and
• Hostile.

The five ascending categories for military capability are:

• Marginal,
• Aspirational,
• Capable,
• Gathering, and
• Formidable.

As noted, these characterizations—behavior and capability—form the two halves of the 2026 Index’s assessment of the threats to U.S. vital interests.

One example of the interplay between behavior and capability centers on Russia’s invasion of Ukraine. Throughout its buildup of forces along the border with Ukraine in the months preceding the war, Russia consistently dismissed observers’ concerns that it was preparing to invade. Russia’s behavior, combined with the military capability it had deployed in posture and geographic position, belied its official pronouncements.

The same thing can be said about our adversaries in China, Russia, Iran, and North Korea. Each of these states repeatedly rejects outside concerns that its activities and capabilities threaten the interests of neighbors or the United States, but no rational country can ignore the threats they pose. As noted earlier, it is helpful for us and our allies when these actors explicitly question the legitimacy of their neighbors or threaten to turn their homelands into seas of fire. Such statements are clarifying.

The United States must therefore take stock of the military capabilities and behaviors of its chief adversaries as it considers the status of its own military.

Defining National Security Interests

The United States has vital security and economic interests and at times must employ its military capabilities to defend those interests. A large percentage of U.S. global trade, for example, comes from Asia and Europe: The Indo-Pacific region and Europe, respectively, account for well over 30 percent and more than 20 percent of America’s overseas trade. This means that America’s prosperity is based in large part on its ability to ensure market access in both regions. Though the United States at this point draws only a fraction of its energy from the Middle East, much of the world still depends on fossil fuels produced in that region. Consequently, any disruption of the production of fossil fuels from the Middle East will have repercussions across the global economy.

Threats to these interests generally come from other countries that have the capability and intent to disrupt them.[REF] China is the primary threat to the United States not just because of the size and capability of its armed forces, but because of its stated intent to disrupt the global order and its active effort to undermine regional, if not global, stability. Additionally, its expanding inventory of nuclear weapons makes it an existential threat to the United States. Russia also has a large inventory of nuclear weapons and, while weakened as a result of its invasion of Ukraine, still maintains a large conventional military with somewhat capable strategic bombers and submarines. Iran poses a regional and indirect threat to core U.S. interests with its nuclear programs, missile inventories, and activities that threaten to destabilize the Middle East. North Korea is a similar but even greater threat because of its maturing nuclear and ballistic missile capabilities that can threaten both its neighbors and the American homeland. Consequently, though China is clearly the primary threat, the United States cannot completely ignore other actors in other regions. Instead, it must work with regional allies and partners in regions of lesser priority, providing its allies with key enabling capabilities while they assume the conventional lead in deterring and if necessary, defeating adversary aggression.

Both the political and economic interests of the United States and its physical safety are at risk when its military does not have sufficient size, readiness, and capability to deter and if necessary, defeat adversary threats to vital American interests. Currently, the military could prevail in one major war if it pulled all of its resources from other theaters to focus on one contingency, but this is not a winning strategy because it leaves the other regions vulnerable to the opportunistic aggression of other regional adversaries. Moreover, the time it would take to pull all forces from all regions and focus those forces on a specific theater of operation would be substantial. In such a timeframe, adversaries might achieve their operational objectives and present the United States with a fait accompli.

As part of this analysis, one must disaggregate national interests from national security. The two are related but not the same; the first drives the second. National security interests are more narrowly defined to focus on things that protect highest-order interests—things that military power can protect so that national culture, values, governance, and global status are preserved from physical threats. As the original 2015 Index of U.S. Military Strength stated:

[N]ational security is not something that merely affects the well-being of Americans. Rather, it involves their safety, their security, and their freedoms.…

National security is the safekeeping of the nation as a whole. Its highest order of business is the protection of the nation and its people from attack and other external dangers by maintaining armed forces and guarding state secrets.…

Because national security entails both national defense and the protection of a series of geopolitical, economic, and other interests, it affects not only defense policy, but foreign and other policies as well. Foreign and defense policies should be seen as mutually reinforcing.…[REF]

The Biden Administration’s October 2022 National Security Strategy violated these precepts by conflating such issues as food insecurity and climate change with national security issues. Food insecurity is indeed a problem; it is just not one that threatens U.S. national security.[REF]

The Trump Administration’s 2025 National Security Strategy reinforces some very similar basic principles and is worth quoting at length:

• Focused Definition of the National Interest. Since at least the end of the Cold War, administrations have often published National Security Strategies that seek to expand the definition of America’s “national interest” such that that [sic] almost no issue or endeavor is considered outside its scope. But to focus on everything is to focus on nothing. America’s core national security interests shall be our focus.
• Peace Through Strength. Strength is the best deterrent. Countries or other actors sufficiently deterred from threatening American interests will not do so. In addition, strength can enable us to achieve peace, because parties that respect our strength often seek our help and are receptive to our efforts to resolve conflicts and maintain peace. Therefore, the United States must maintain the strongest economy, develop the most advanced technologies, bolster our society’s cultural health, and field the world’s most capable military.
• Predisposition to Non-Interventionism. In the Declaration of Independence, America’s founders laid down a clear preference for non-interventionism in the affairs of other nations and made clear the basis: just as all human beings possess God-given equal natural rights, all nations are entitled by “the laws of nature and nature’s God” to a “separate and equal station” with respect to one another. For a country whose interests are as numerous and diverse as ours, rigid adherence to non-interventionism is not possible. Yet this predisposition should set a high bar for what constitutes a justified intervention.
• Flexible Realism. U.S. policy will be realistic about what is possible and desirable to seek in its dealings with other nations. We seek good relations and peaceful commercial relations with the nations of the world without imposing on them democratic or other social change that differs widely from their traditions and histories. We recognize and affirm that there is nothing inconsistent or hypocritical in acting according to such a realistic assessment or in maintaining good relations with countries whose governing systems and societies differ from ours even as we push like-minded friends to uphold our shared norms, furthering our interests as we do so.
• Primacy of Nations. The world’s fundamental political unit is and will remain the nation-state. It is natural and just that all nations put their interests first and guard their sovereignty. The world works best when nations prioritize their interests. The United States will put our own interests first and, in our relations with other nations, encourage them to prioritize their own interests as well. We stand for the sovereign rights of nations, against the sovereignty-sapping incursions of the most intrusive transnational organizations, and for reforming those institutions so that they assist rather than hinder individual sovereignty and further American interests.
• Sovereignty and Respect. The United States will unapologetically protect our own sovereignty. This includes preventing its erosion by transnational and international organizations, attempts by foreign powers or entities to censor our discourse or curtail our citizens’ free speech rights, lobbying and influence operations that seek to steer our policies or involve us in foreign conflicts, and the cynical manipulation of our immigration system to build up voting blocs loyal to foreign interests within our country. The United States will chart our own course in the world and determine our own destiny, free of outside interference.
• Balance of Power. The United States cannot allow any nation to become so dominant that it could threaten our interests. We will work with allies and partners to maintain global and regional balances of power to prevent the emergence of dominant adversaries. As the United States rejects the ill-fated concept of global domination for itself, we must prevent the global, and in some cases even regional, domination of others. This does not mean wasting blood and treasure to curtail the influence of all the world’s great and middle powers. The outsized influence of larger, richer, and stronger nations is a timeless truth of international relations. This reality sometimes entails working with partners to thwart ambitions that threaten our joint interests.
• Pro–American Worker. American policy will be pro-worker, not merely pro-growth, and it will prioritize our own workers. We must rebuild an economy in which prosperity is broadly based and widely shared, not concentrated at the top or localized in certain industries or a few parts of our country.
• Fairness. From military alliances to trade relations and beyond, the United States will insist on being treated fairly by other countries. We will no longer tolerate, and can no longer afford, free-riding, trade imbalances, predatory economic practices, and other impositions on our nation’s historic goodwill that disadvantage our interests. As we want our allies to be rich and capable, so must our allies see that it is in their interest that the United States also remain rich and capable. In particular, we expect our allies to spend far more of their national Gross Domestic Product (GDP) on their own defense, to start to make up for the enormous imbalances accrued over decades of much greater spending by the United States.
• Competence and Merit. American prosperity and security depend on the development and promotion of competence. Competence and merit are among our greatest civilizational advantages: where the best Americans are hired, promoted, and honored, innovation and prosperity follow. Should competence be destroyed or systematically discouraged, complex systems that we take for granted—from infrastructure to national security to education and research—will cease to function. Should merit be smothered, America’s historic advantages in science, technology, industry, defense, and innovation will evaporate. The success of radical ideologies that seek to replace competence and merit with favored group status would render America unrecognizable and unable to defend itself. At the same time, we cannot allow meritocracy to be used as a justification to open America’s labor market to the world in the name of finding “global talent” that undercuts American workers. In our every principle and action, America and Americans must always come first.[REF]

Security Interests. To this end, the security interests that these goals underwrite should be limited in number and clearly defined. Top-level national security documents issued by multiple presidential Administrations have consistently made clear that, as noted above, three principal security interests are central to any assessment of national military power:

1. Defense of the homeland,
2. Successful conclusion of a major war, and
3. Preservation of freedom of movement across free and open air and maritime lanes.

These interests help the military to determine how much military power is needed, how it should be organized and employed, and where it should be deployed to achieve maximum effect. An analysis of these security interests reflects that the nation’s interests and the challenges to those interests exist in several regions around the world. They are not limited to any one region because America’s prosperity and security depend on and are affected by multiple regions.

Economic Interests. Fifteen countries and regions (e.g., South and Central America and the European Union) account for approximately 87 percent of all U.S. trade. Canada and Mexico represent 15.4 percent of the total; six of the top 15 countries responsible for 44 percent of U.S. trade are in Asia; six in Europe account for 26 percent; and the remaining countries and regions (e.g., Brazil, Mexico, and South and Central America) account for 20 percent.[REF]

The top five U.S. trading partners are Mexico (13.6%); Taiwan (12%); Vietnam (11%); China (10%); and Switzerland (5.6%). Of the remaining 10, five countries and regions in Europe (the United Kingdom, the Netherlands, Germany, Ireland, and the European Union) account for 20 percent of trade, and three in Asia (Hong Kong, Japan, and South Korea) account for 7.5 percent.[REF]

These data illustrate that the economic interests of the U.S. are linked to more than one region; they include the Americas, Europe, and a broad expanse of the Indo-Pacific. To the extent that military power buttresses diplomatic initiatives and strengthens economic relationships, the United States cannot afford to focus on just one region. It must maintain the capacity for military presence and action in those key regions concurrently with capabilities that are relevant to the geography involved, the ability of allies to contribute to the defense of common interests, and the ability of potential enemies to impose their will.

However, U.S. interests are not defined solely by direct trade relationships with specific countries or regions. America’s economic partners also have trade and financial relations with others, notably China. For example, while the United States might not be as dependent on fossil fuels from the Middle East as other countries are, the fact that many of its partners do depend on this source of energy must be factored into any assessment. Disruption of the flow of energy for any meaningful length of time could have a devastating impact on those countries with which the U.S. trades and lead to serious indirect consequences for the United States itself. Moreover, disruption need not come from conflict; it can be the result of an economic competitor’s taking a larger share of a market at the expense of the United States.

With respect to the broader Middle East, in 2023, just over half of China’s oil imports—approximately 52 percent—came from the Gulf region with 17.2 percent coming from Saudi Arabia alone, amounting to $162.14 billion.[REF] The United States cannot ignore this non-U.S. economic relationship in its national security calculations.

In terms of trade relationships, the United States remains China’s largest single trading partner, importing $524.9 billion worth of Chinese goods and accounting for 14.7 percent of China’s exports in 2024, but China also has other partners. In Europe, China’s exports to the Netherlands, Germany, and the United Kingdom total $315.4 billion, a bit more than half of what it exports to the United States. In Asia, China’s exports to its top 10 regional partners amount to $1,312.3 billion or 36.6 percent of total exports—three times the amount it exports to the U.S.[REF]

The United States maintains a range of relationships with a diverse array of countries for one purpose: to ensure that its interests are protected not just in one region, but globally to account for various threats that differ in their character and magnitude. In all of these relationships, it is important for the U.S. to be seen as a powerful, reliable, and capable actor that can be counted on by friends and must be accounted for by foes. Diplomatic presence is important, as is a robust economic relationship, but it is more important that America’s military presence is maintained in prioritized regions because military power maintains the peace where these other endeavors take place. Geographically present military force is essential to reassuring friends and deterring enemies, but it may not necessarily be sufficient to fully protect national interests. If deterrence fails, the United States must be able to project additional combat power and sustain operations. This implies sufficient strategic sealift, airlift, and logistical sustainment to move and support military forces and enable them to respond in mass to defeat an enemy attack. But this response capability must not come at the expense of risking key national interests in areas that are not under immediate attack: Capacity to respond and protect matters.

Endnotes