America’s Delicate Dance Between Deterrence and Assurance

America’s Delicate Dance Between Deterrence and Assurance

With allies and adversaries alike, U.S. diplomacy is a complex exercise.



Like with its allies, the United States deters and assures its adversaries. Unlike during the Cold War, however, it adopts different approaches for different potential adversaries. Back then, Washington viewed almost everything through the lens of a monolithic Soviet threat. Today, facing a more diverse and independent set of potential adversaries, the United States tailors its approach to each, using both nuclear and non-nuclear tools. In particular, U.S. policy toward Russia and China differs considerably from its approach to North Korea, and this has important implications for both deterrence and assurance.

With Russia and China, states that are not strictly categorized as U.S. adversaries, Washington accepts mutual vulnerability—explicitly with Moscow and implicitly with Beijing—as the operating model for stable relations. It seeks to assure them that it will avoid developing and deploying capabilities that could negate their retaliatory nuclear forces, reducing the incentive for either the United States or its potential adversaries to deploy additional nuclear forces or use nuclear weapons first in a crisis for fear of a disarming first strike. With both states, the United States also seeks to improve strategic stability, building upon the many economic, political and security interests that they share, while steering clear of potential military flashpoints. With Russia, the only country with which it shares a similar-sized nuclear arsenal, the United States seeks to do so by advancing the existing bilateral arms-control process currently codified in formal agreements like the New Strategic Arms Reduction Treaty (New START) and the INF Treaty, while simultaneously pursuing broader strategic dialogue in forums such as the NATO-Russia Council. With China, the United States hopes to initiate a similar dialogue on strategic stability, which it has long requested, and, ultimately, to develop an arms-control relationship.

So far, however, there has been little progress. The prospects, in fact, are dim. Russia has invaded Ukraine, violated the INF Treaty, and maintained an important role for nuclear weapons in its military doctrine, clearly identifying the United States and other NATO members as its enemies and spelling out conditions under which it would launch a preemptive nuclear strike. Over the past several months, Moscow has also taken important steps to modernize its nuclear forces. Meanwhile, in addition to showing increasing assertiveness in the maritime domain, China continues to modernize and expand its nuclear arsenal and its conventional forces. While there has been successful track-1.5/2 dialogue between the United States and China, Beijing continues to resist official government dialogue on nuclear weapons and strategic capabilities, raising suspicions in Washington about its policies, thinking and intentions.

Unlike with Russia and China, the United States rejects mutual vulnerability as the basis of its strategic relationship with North Korea. It maintains the option of carrying out a disarming strike, or even going further and pursuing regime change. But, of course, having the option to disarm does not mean the United States will use it. In certain instances, Pyongyang may do something so deplorable or seemingly irrational that Washington would accept nothing less than regime change. In other scenarios, such as the one played out in Maui, the United States may instead opt to retaliate, deter and punish, but keep its aims limited and assure its adversary that it has a way of exiting the crisis.

Like with allies, the United States faces several challenges because it uses different approaches with different adversaries. In rejecting mutual vulnerability with North Korea, for instance, the United States maintains a missile defense architecture designed to counter the evolving ballistic-missile threat that Pyongyang poses to its homeland, the forces it deploys overseas, and its allies. As laid out in the Ballistic Missile Defense Review Report, Washington attempts to do so while assuring China and Russia that its deployments are “not intended to affect the strategic balance.” But as North Korea’s missile program improves, the United States continues to research technologies to stay ahead of the curve and deploy additional, more sophisticated interceptors. This complicates its task of assuring China and Russia that U.S. capabilities will not grow to the point that they do affect the strategic balance. Linton Brooks and Mira Rapp-Hooper describe this as a “security trilemma.”

As a result, the Shanghai Cooperation Organization, led by China and Russia, stressed in its latest declaration that “the unilateral and unlimited strengthening of missile defense systems by any individual state or any group of states will undermine international security and strategic stability.” China and Russia have also voiced objections to the deployment of Terminal High Altitude Area Defense (THAAD) batteries in South Korea. Washington, of course, regularly reminds both Beijing and Moscow that more efforts on their part to limit and rollback Pyongyang’s capabilities would help phase out this trilemma, but, for the most part, Russia and China have been unwilling to exert substantial pressure.


Allies and Adversaries

U.S. policy vis-à-vis its adversaries also has implications for its relationships with its allies, and vice versa. In 1984, Glenn Snyder explained that “the security dilemma occurs in relations between allies as well as between adversaries […] Choices in each dilemma are constrained not only by predicted or feared effects internal to itself, but also by side effects in the other dilemma. In particular, strategy choices in the adversary game—conciliation or firmness—are constrained by fears of abandonment or entrapment by allies.” Thirty years later, Snyder’s words continue to ring true.

Decisions that the United States makes to assure or deter its allies have consequences for its relationships with its adversaries. On one end of the spectrum, too much U.S. restraint or constraint of allies can reduce its ability to deter adversaries. For that reason, Washington has been, however cautiously, encouraging its allies in Northeast Asia and Europe to participate in collective efforts to strengthen regional security architectures through the development of effective missile defense, conventional strike capabilities, and integrated command and control systems.

At the other end of the spectrum, too much U.S. assurance of allies can also create serious problems. For example, believing that Taiwan had unconditional U.S. support, President Chen Shui-bian, whose Democratic Progressive Party ruled in Taiwan from 2000 to 2008, began to push for Taiwanese independence. Washington was quick to respond by clarifying its position, stressing that it would defend its ally against an unprovoked attack from China, but that it would not support unilateral moves toward independence. The United States thereby deterred Taipei from excessive action and assured Beijing that its “one China” policy had not changed. A similar dynamic played out in the fall of 1956 when Israel, followed by Britain and France, invaded Egypt to regain Western control of the Suez Canal. The three U.S. allies initially attained their military objectives, but wrongly assumed that they would receive U.S. support and were eventually forced to withdraw. Washington showed Tel Aviv, London and Paris that U.S. alliances do not give allies carte blanche to do anything they want and expect U.S. support.

By the same token, the decisions that the United States makes to deter or assure its adversaries have a direct impact on its allies. Too much U.S. deterrence of adversaries can make U.S. allies nervous. In a discussion of Western European defense during the Cold War, Michael Howard argues that “proposals to make nuclear war ‘fightable,’ let alone ‘winnable,’ by attempting to limit its targets and control its course, however much sense this may make in the military grammar of deterrence, are not persuasive in the political language of reassurance.”

On the other hand, too much U.S. assurance of adversaries can, by contrast, create fears of abandonment among U.S. allies. While Washington is committed to developing stable strategic relations with Beijing, many U.S. officials and experts feel that the United States cannot publicly accept mutual vulnerability with China, at least in part because of resistance from the Japanese, who believe that such an acknowledgement would signal weakness and embolden China to more assertively promote its interests at Japan’s expense. Many in Japan argue that U.S. acknowledgement of mutual vulnerability would decrease Japan’s security.


Conclusions and Recommendations

The United States constantly balances deterrence and assurance with both its allies and adversaries. With allies, the United States is primarily concerned with offering protection to maintain lasting partnerships that guard its regional and global interests, but it also seeks to prevent nuclear proliferation and to avoid being drawn into unwanted wars. With adversaries, the United States maintains a robust military posture to deter them from challenging U.S. interests or those of its allies, but it also signals the limits of U.S. intentions, offering them security in peacetime and off-ramps during crises. With both allies and adversaries, the United States must manage its messages because they are heard by multiple audiences at once. This is a difficult task because the United States uses different approaches with different allies and adversaries, sometimes creating issues and even tensions not only between allies and adversaries, but also among allies and among adversaries.

Washington, therefore, must weigh benefits, costs, and risks as it dances between assurance and deterrence of allies and adversaries, recognizing that it will often have to make less than optimal compromises. So far, the United States has done well in managing these challenges, but the task of aligning U.S. policy to the changing security environment is a constant work-in-progress.