Under Presidents Barack Obama, Donald Trump, and Joe Biden, U.S. defense strategy has been premised on the optimistic notion that the United States will never need to fight more than one war at a time. During the Obama administration, in the face of fiscal austerity, the Defense Department abandoned its long-standing policy of being prepared to fight and win two major wars to focus on acquiring the means to fight and win just one. That move accelerated the trend toward a smaller U.S. military. It also narrowed the options available to U.S. policymakers, given that committing the United States to war in one place would preclude military action elsewhere.

This switch was misguided then, but it is especially out of step today. The United States is currently involved in two wars—Ukraine’s in Europe and Israel’s in the Middle East—while facing the prospect of a third over Taiwan or South Korea in East Asia. All three theaters are vital to U.S. interests, and they are all intertwined. Past efforts to deprioritize Europe and disengage from the Middle East have weakened U.S. security. The U.S. military drawdown in the Middle East, for instance, has created a vacuum that Tehran has filled eagerly. A failure to respond to aggression in one theater can be interpreted as a sign of American weakness. Allies across the world, for example, lost faith in Washington after the Obama administration failed to enforce its “redline” against chemical weapons use by Syria. And the United States’ adversaries are cooperating with one another: Iran sells oil to China, China sends money to North Korea, and North Korea sends weapons to Russia. The United States and its partners face an authoritarian axis that spans the Eurasian landmass.

Washington is fortunate to have capable allies and friends in East Asia, Europe, and the Middle East. Collectively, they have the power to help it constrain the authoritarian axis. But to succeed, they must do a better job of working together. Washington and its allies need to be what military planners call interoperable: capable of quickly sending resources across an established system to whichever ally needs them most. The West, in particular, must create and share more munitions, weapons, and military bases. The United States also needs to formulate better military strategies for fighting alongside its partners. Otherwise, it risks being overwhelmed by its increasingly capable and intertwined enemies.

PUTTING FRIENDS FIRST

The first effort the United States and its allies must step up is defense production. The West has long been home to the most capable and sophisticated armaments in the world. But right now, it simply does not manufacture enough materiel.

Consider munitions. The wars in both Gaza and Ukraine have shown that modern conflict is munitions-intensive and protracted. The Ukrainian army fires thousands of artillery shells per day, at times outstripping the production capability of its suppliers. Israel has gone through thousands of tank rounds and fired many precision-guided munitions in its war with Hamas since October 7. Collectively, the U.S.-supported Ukrainian and Israeli war efforts amount to an expenditure rate that Western munitions companies are struggling to meet. As a result, the United States and its allies have had to make difficult choices about which munitions they can send to friends and which they need to keep for themselves.

In major wars, no country, not even the world’s strongest, can go it alone.

As the alliance’s central member and main security provider, the United States must be able to meet the needs of both its own and its allies’ armed forces. To do so, the U.S. government should provide defense companies with the kind of steady demand needed to boost production. Congress took an important step in this direction last year, when it authorized the Pentagon to buy multiple years’ worth of munitions, providing manufacturers with long-term contracts. But by failing to pass a budget promptly, Congress undercut this laudable attempt to create a steady demand for munitions. Congress should mandate that the Defense Department set minimum munitions stockpile levels and create a mechanism to restock automatically once munitions are sold or expended to balance supply and demand.

To better position both itself and its allies, however, Washington must do more than simply make lots of munitions. It must also get better at creating a seamless distribution process. Domestic and foreign orders of American arms are fulfilled through the same assembly lines, but procedurally, foreign military sales are segregated from U.S. ones, with the former controlled by the State Department and the latter by the Defense Department. This division can make it hard to adjust supply to meet demand. Bureaucracy makes the foreign military sales process slow and cumbersome. And even when such sales are approved, allies are generally sent to the back of the line, where they can wait years to obtain weapons that they have already paid for and that may be essential to deterring imminent attacks. To solve this problem, the United States must streamline and speed up the process for foreign clients. It should allow the Defense Department to include foreign sales as part of the demand signal it sends to industry and cut back on rules that keep allies waiting behind U.S. contracts.

Fulfilling foreign munitions sales before meeting the needs of the U.S. armed forces may seem harmful to American interests, even when those countries made their purchases first. There are certainly moments when Washington’s needs should take precedence. But allowing defense firms to ship to Taiwan or Poland before Fort Bragg when necessary can enhance U.S. security—especially when the United States is not itself fighting major wars. The effort to supply Ukraine, for example, is a truly multinational affair, featuring the United States and its allies in NATO and throughout Europe and Asia. By checking Russian aggression, these countries promote Washington’s security as well as their own. U.S. allies have also expanded their own munitions industries to help Ukraine fight Moscow, which ultimately lessens the demands on the United States. Washington can encourage these countries to keep expanding production by making sure they know that when they do need U.S. wares, their orders won’t be treated as second class.

WHAT’S MINE IS YOURS

The United States has plenty of weapons it can sell to its friends. It is a global leader in advanced combat aircraft, nuclear-powered submarines, space capabilities, and software, and it should develop many of these capabilities with an intent to export them. For example, the U.S. Air Force’s state-of-the-art B-21 Raider stealth bomber could be useful to U.S. allies such as Australia, who need the ability to strike over long distances, but a reluctance to export advanced technology stands in the way of providing close partners with the best available equipment. U.S. policy should ensure that American political leaders have the option to supply such advanced systems to close allies.

Fortunately, Washington has valuable experience with sharing its military technology. Besides the United States, seven nations—Australia, Canada, Denmark, Italy, the Netherlands, Norway, and the United Kingdom—are partners in the F-35 combat aircraft program, and an additional nine have agreed to purchase the aircraft. These aircraft are supported by a truly global logistics and maintenance infrastructure. The AUKUS agreement offers another example; it provides a path for Australia to acquire nuclear-powered submarines and for the United Kingdom to bolster its underwater capabilities. AUKUS has also helped Washington by exposing the limits of its shipbuilding industry. The deal has made it clear that American manufacturers are not large enough or capable enough to modernize the U.S. submarine fleet as well as build submarines for Australia, prompting Australia to invest $3 billion in expanding the United States’ submarine industrial base. The result will serve both U.S. and Australian interests.

Allies can help the U.S. defense base in other ways, as well. The United States is a global leader in some defense manufacturing areas, but many of its allies have comparative advantages in others. Although the U.S. shipbuilding industry has shrunk, Japan and South Korea have impressive shipyards that Washington can tap. Israel produces excellent air and missile defense systems such as the Iron Dome, and Norway fields excellent antiship missiles. Washington should do more to encourage these allies to share their own top-tier technologies.

Expanding such cooperation will not be easy. The defense industry—and the jobs and funding that go with it—are the stuff of domestic politics, both in Washington and in allied capitals. That is why, even in areas in which Congress has sought to promote collaboration, defense officials have run into bureaucratic obstacles. Australia, Canada, and the United Kingdom are considered part of what American law calls the U.S. National Technology and Industrial Base, which consists of the people and organizations engaged in national security and dual-use research, development, and production. But domestic sourcing requirements and standard operating procedures nonetheless stand in the way of deep collaboration among these friends. There are strong political incentives to keep such barriers in place, such as concerns over domestic jobs, but U.S. officials would be wise to stand up to such pressure and eliminate them. It is tempting to force companies to buy everything at home, but Americans will ultimately be more secure and prosperous if their country has access to more and better defense products, regardless of their provenance.

MOVING AS ONE

The United States possesses an unparalleled network of global military bases, one that has allowed it to project power for over a century. Some of these bases are on U.S. territory, from Guam in the Western Pacific to Maine on the East Coast of the United States. Others are on allied territory, designed to reassure U.S. friends and deter U.S. enemies. But all these bases have become more vulnerable, as adversaries have acquired the ability to strike with precision over great distances (as Iran and Russia have both done over the last six months). To be fully interoperable, the United States and its partners will therefore need to be better at protecting their bases and moving assets around.

In recent years, the U.S. Air Force has developed what it calls “agile combat employment” as a way of operating against a capable adversary. This strategy entails operating combat aircraft from dispersed bases so they can’t be easily targeted. Similarly, the U.S. Navy has begun learning how to strike targets from dispersed ships, aircraft, and submarines. But the effectiveness of these concepts, and ultimately U.S. power, rests on forward bases and logistical support, including on allied territory. Washington and its partners must therefore find more places to station their troops and store their weapons.

In the Western Pacific, Japan offers some promising locations for dispersed operations. The country has many ports, airfields, and support facilities that are tied into the Japanese road and rail network. But existing arrangements restrict Japan’s military to a small fraction of these facilities, and U.S. forces are restricted to an even smaller portion. The United States should encourage the Japanese government to expand both militaries’ access to militarily useful airfields and ports rather than largely restricting it to designated U.S. bases.

History shows that Americans perform best when they fight side by side with allies.

In the meantime, the United States may be able to rotate more troops through northern Australia. Australia is far enough away from China to be safe from most Chinese air and missile threats but still close enough to conduct and support operations in a future conflict in the Western Pacific. And there is precedent: during World War II, the landscape of northern Australia was dotted with airfields from which American and Australian pilots fought against Japan. The remnants of many of these facilities still exist, ready to be resurrected. Australia and the United States simply need to renovate and expand them.

The United States and its allies must also get better at defending their facilities against ever more capable missiles. They must move beyond the traditional approach to air and missile defense, which depends on using small numbers of expensive interceptors, to one that features directed-energy weapons (such as lasers or electromagnetic-pulse weapons), large numbers of low-cost interceptors, and sensors that can provide the information necessary to defeat large, complex attacks, such as the one that Iran launched against Israel in April. Australia, Japan, and the United States have made progress by calling for the development of a networked air and missile defense architecture to defend each other. Now, they must follow through.

Expanded basing will further contribute to interoperability. By training and operating more closely with one another in peacetime, U.S. and allied forces will develop habits of cooperation that will serve them well in wartime. Allies may be able to strike deals, for example, that will allow them to quickly surge forces and resources to bases across theaters, as needed, to deter threats or respond to aggression.

SHARING IS CARING

The United States and its partners need to cooperate more closely on munitions, military basing, and the defense industry more broadly. But interoperability means more than exchanging physical resources. The West will also need to do a better job of coming up with shared concepts and strategies. Washington must have frank conversations with its allies to help clarify assumptions about objectives, strategy, roles, and missions and yield a better understanding of how best to work collectively.

Take, for instance, the development of new ways of war. During the Cold War, the army and air force developed strategies for how to defeat a Soviet attack on NATO in Central Europe, some of which remain in use. Today, the U.S. military is developing a series of new, internal operational concepts tailored to modern warfare. But Washington should open this process to close allies, both to learn from them and to ensure that they are best positioned to operate with the United States in times of conflict. For example, the United States and key allies such as Australia, Japan, and the Philippines must figure out how to work together to meet the threat of Chinese aggression against Taiwan.

The United States, of course, cannot share everything—physical or ideational—with its partners. Some weapons should never be shared. But history shows that Americans perform best when they fight side by side with allies. They are most likely to win wars on multiple fronts when they work with multiple partners. As Washington faces growing dangers in three regions, it must learn how to better cooperate and share with its many friends. In major wars, no country, not even the world’s strongest, can go it alone.

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  • THOMAS G. MAHNKEN is President and CEO of the Center for Strategic and Budgetary Assessments and a Senior Research Professor at Johns Hopkins School of Advanced International Studies.
  • More By Thomas G. Mahnken