National security specialists talk about deterrence a lot. Like, a lot. Analysts are churning out a steady stream of articles debating how best to deter a variety of actors from taking a variety of unwanted actions in a variety of domains and/or using a variety of weapons. As the author of one such piece put it, “The deterrence message is broadcasting on all channels.”
What gets lost, however, in all these separate debates over distinct foreign-policy issues is how much of a role deterrence actually plays in U.S. national security strategy writ large, how that role is changing over time, and what factors are driving that shift. A popular contemporary conception views strategy as the identification and balancing of ends, ways, and means. Deterrence, defined as “discouraging an action or event through instilling doubt or fear of the consequences,” is a key way actors may try to achieve their ends. But despite its continued prominence in national security discussions, the actual role of deterrence in U.S. policy has declined in recent decades, due to expanding U.S. objectives – along with the strategic problems this expansion has ushered in – and increasing U.S. capabilities. This longer-term shift has only been exacerbated and made more obvious by the current administration.
One Option Among a Menu of “Ways”
The shortcomings of deterrence as a “way” are well-known. Most immediately, deterrence can work only against rational actors who make cost-risk-benefit calculations. Many believe, however, that non-state actors, and possibly some states, are driven by religious or ideological imperatives instead of the kinds of strategic calculations deterrent efforts can hope to influence. And deterrence can fail even against actors who do make those sorts of calculations. Factors such as strategic culture, degree of shared understanding, internal political dynamics, and biases and risk orientations can all systematically skew others’ decision making in ways U.S. planners may not understand. Each of these limitations will reduce the role deterrence plays in any nation’s strategy.
More relevant than deterrence’s strengths and weaknesses in a vacuum, however, is the extent to which deterrence is actually a relevant way of attaining U.S. goals. Actors have a broad menu of ways from which to choose to try and achieve their objectives. These can be divided into what Thomas Schelling called “brute force” vs. “coercion” (or what Lawrence Freedman calls “controlling” vs. “coercive” strategies). Brute force is all about capabilities: trying to build up one’s own and/or degrade those of others in order to make others less able to harm U.S. interests. Imposing economic sanctions on Iran, for instance, could be part of a brute-force effort if the point was to reduce Tehran’s ability to take some unwanted action, such as developing nuclear weapons – e.g., by limiting the Iranians’ access to key materials. Common concepts such as “offense,” “defense,” “damage limitation,” “preemption,” “prevention,” “rollback,” and “resiliency” all fall under this umbrella.
Coercion, on the other hand, is all about choices: trying to influence others’ decision making in order to make them less likely to try to harm U.S. interests in the first place. There are two variants of coercion: Deterrence seeks to convince others to maintain their current choices or behaviors, while compellence – a word coined by Schelling that never quite caught on – seeks to convince others to change their choices or behaviors. Sanctions against Iran could be part of a coercive effort if U.S. policymakers believed the threat or actual imposition of sanctions would shape Tehran’s cost-benefit calculations in such a way as to convince Iranian leaders to do what Washington wanted. Understanding deterrence and its place in the broader menu of strategic “ways” helps us see how the relative importance of each way has changed over time.
The Declining Role of Deterrence
During the Cold War, deterrence took pride of place in U.S. national security strategy, and for good reason. While some U.S. policymakers and analysts never gave up on the dream of circumventing “mutually assured destruction,” most understood that brute force was not an option when it came to the primary threats facing the country – thermonuclear war with a Soviet Union whose arsenal had reached rough parity with that of the United States and large-scale conventional war with a Warsaw Pact that overmatched NATO. This left coercion as the only broad option. Within the types of coercive strategies, compelling the Soviet Union to voluntarily make concessions was a non-starter, largely for the same reasons. The best the United States could hope to achieve was to deter Soviet attempts at further gains. Americans may never have embraced deterrence but most accepted that there simply weren’t any other real options.
However, since the Cold War, three changes have considerably reduced the role deterrence plays in U.S. strategy. First, the United States in many important respects no longer seeks to maintain the status quo, which means that even 100 percent successful deterrent efforts cannot achieve U.S. objectives. The collapse of the Soviet Union meant a loosening of constraints on the exercise of U.S. power, and U.S. goals have expanded accordingly. In each portion of the “four-plus-one” threat framework that the Department of Defense currently uses to guide planning and prioritization, the goal is to revise the relevant circumstances in America’s favor, not to maintain them. Specifically, U.S. leaders seek to slow, halt, or, ideally, roll back Chinese efforts in the South and East China Seas, Russian subversion of U.S. allies and partners in its perceived “near abroad,” Iranian pursuit of increased power and prestige in the Persian Gulf, North Korean progress on its nuclear weapons and related delivery vehicle programs, and violent extremist organizations’ increasing entrenchment across large swaths of the globe. Given these objectives, if the United States attempts to engage in coercive approaches, they are likely to involve compellence, or attempts to change the status quo, not deterrence.
Second, this expanded security framework geared towards changing the status quo means that in a number of circumstances, coercive strategies broadly – whether deterrent or compellent – may simply not be viable. Adversaries might perceive the benefits of defying U.S. wishes to be so high that there is no cost the United States can threaten that would convince them to cooperate. Efforts to acquire, maintain, and expand nuclear arsenals might fall into this category. For instance, North Korean leader Kim Jong Un likely views his country’s nuclear weapons and delivery systems as the only means of guaranteeing his hold on power. It is hard to imagine what the United States could threaten that could outweigh this perceived benefit of remaining a nuclear-armed state and thereby convince him to scale back, much less give up, his nuclear arsenal.
Adversaries might also perceive the costs of defying U.S. wishes to be so low that there is no reason not to try, even if they think success is unlikely. As Washington pays greater attention to newer domains, others’ efforts to harass the United States, its interests, and allies in or through cyberspace might fall into this category. Cyber espionage efforts in particular are intensifying and spreading around the globe, in part because of how inexpensive they are for states to conduct. (And of course, low perceived retaliatory costs also undermine U.S. efforts to convince others, such as China, to change their behavior.)
Regardless of what they expect the consequences of defiance to be, adversaries might also perceive the benefits of complying with U.S. demands to be of such doubtful reliability that there is no reason to do so. For coercion to work, a state or group needs to believe not only that the United States has the capability and will to carry out any threatened action should that actor defy U.S. wishes, but also that the United States will refrain from carrying out the threat should the actor in fact comply. Since the Cold War, U.S. leaders have repeatedly shown that it will carry out threats even if the adversary complies with American aims. Supporters of George W. Bush’s decision to attack Iraq didn’t withdraw their backing when the initial justification for the war collapsed; Barack Obama pursued regime change in Libya despite the fact that Moammar Qaddafi had given up his nuclear program; and Donald Trump decertified the Iran nuclear deal even though Tehran is complying with its terms. This bipartisan track record signals that Washington can’t be trusted to uphold its end of a bargain, which will likely make it harder for the United States to convince others to act in accordance with its wishes in the future.
Third, advances in intelligence and technology may have made brute force a more viable option for some security concerns. Policymakers certainly seem to think this is the case. At the high end of the conflict spectrum, analysts argue that the United States is better able to locate and destroy concealed and hardened nuclear weapons delivery systems, their command-and-control sites, and the secure means of transmitting their launch orders. As a result, preventive or preemptive strikes might be able to meaningfully limit the damage the United States or its forces or friends would suffer in any retaliatory strike. National Security Advisor H.R. McMaster and other administration officials seem to believe this can be done with respect to North Korea. Even some critics of such an attack believe the United States nonetheless has the capability to remove the threat posed by Pyongyang “in one swift blow.” And Trump himself has expressed great confidence, however ill-founded, that U.S. missile defense systems could handle North Korean intercontinental ballistic missiles. Believing that U.S. forces, allies, and even cities can be defended against retaliatory strikes makes a U.S. first strike – a classic example of brute force – appear viable.
At the low end of the spectrum, the intelligence-operations fusion allowed by the find, fix, finish, exploit, analyze, and disseminate (F3EAD) targeting methodology has exponentially increased the number of suspected insurgents taken off the battlefield. F3EAD was first developed by U.S. special operations forces in Iraq and subsequently extended to general-purpose forces and around the globe. U.S. commanders seem to genuinely believe these tactical and operational achievements have produced strategic effects by breaking insurgent networks. While Trump has been less clear as to how such efforts would achieve U.S. objectives, he has been adamant that the United States stop nation-building and focus instead on “killing terrorists.” Across a range of contingencies, then, brute force appears to have gained ground.
In sum, deterrence no longer supports many U.S. objectives, there are a number of circumstances in which coercion in general is less likely to work, and there are many others in which brute force might work – and in which U.S. leaders clearly think it will or already does.
These shifts in the relative importance of various “ways” are likely to hamstring U.S. national security strategy in the coming years. Brute force is unlikely to be useful in dealing with the wide range of challenges posed by Russia and China. This leaves coercion as an obvious approach. But successfully influencing others has gotten increasingly difficult for Washington since the Cold War, given the expansion of U.S. objectives on the one hand and adversaries’ resultant concern about regime survival, the decreasing costs of challenging U.S. interests, and the declining credibility of U.S. assurances on the other. The current administration’s sidelining of the intelligence community and gutting of the State Department has only further thinned America’s strategic toolkit, reducing Washington’s ability to acquire the type of information that could help policymakers design and implement coercive efforts with a better chance of success. And finally, in a shift from a grudging acceptance of the status quo during the Cold War, U.S. policymakers now seek to revise it in a number of important areas, leaving even less room for deterrence in U.S. strategy.
National security specialists will no doubt continue to talk about deterrence. But its role in U.S. strategy has declined considerably. Diagnosing how and why that has happened is an important addition to the conversation – particularly for those who hope to one day bring deterrence back in from the cold.
T. Negeen Pegahi is an assistant professor of strategy and the director of the Mahan Scholars research program at the U.S. Naval War College. The views expressed here are her own and do not necessarily reflect those of the Naval War College, the Department of the Navy, the Department of Defense, or the U.S. government.
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