Politics & Diplomacy

Reality Check

March 1, 2021

Reality Check #3: The uses and abuses of deterrence

By Erica Borghard

Key points

  • Policymakers tend to describe as “deterrence” actions or situations that are, in fact, coercive. Most recently, the commander of US Central Command described the United States as in a state of “contested deterrence” with Iran.
  • However, deterrence and coercion are different concepts. Confusing these terms leads to muddled strategy and poor communication.
  • Policymakers should be deliberate about how they talk about US strategy, and take care to avoid defaulting to deterrence language to describe actions that are not deterrence.

What’s the issue?

On February 8, General Kenneth McKenzie, the commander of US Central Command, described in a speech at the Middle East Institute that the United States is currently in a period of “contested deterrence” with Iran. The term “contested deterrence” is only one of a number of permutations of deterrence that policymakers and senior leaders have used to describe actions they seek to convey as such. For instance, in January 2020, then-Secretary of State Mike Pompeo delivered an address titled “The Restoration of Deterrence: The Iranian Example.” In the speech, Pompeo described the Donald Trump administration’s goals toward Iran as “re-establishing deterrence—real deterrence.” Similarly, Trump’s former national security advisor, General H.R. McMaster, described in his book, Battlegrounds: The Fight to Defend the Free World, the US strike that killed Qasem Soleimani and Abu Madhi al-Muhandis, as well as economic sanctions against Iran, as policies aimed at “restoring deterrence of Iran.” Likewise, retired General David Petraeus described the Soleimani strike as enabling the United States to “reestablish deterrence” against Iran.

The problem with all of these variants of deterrence is that what they describe is not, in fact, deterrence. Instead, in most cases, they describe coercion. Coercion and deterrence are related concepts in that they aim to affect another state’s behavior by manipulating its perception of the costs, risks, and benefits of a given action. However, they are different in two important respects: they have distinct end states and different manifestations, particularly with respect to the use of force.

If deterrence is contested, has to be reestablished, or is in need of restoration, then deterrence has failed.

First, deterrence seeks to maintain the status quo and prevent an adversary from taking some action it has not yet taken. For example, as part of Operation Desert Shield during the Persian Gulf War, the United States deployed five hundred thousand troops to Saudi Arabia to deter Saddam Hussein from attacking Saudi Arabia—an action that was feared, but not taken. In contrast, coercion seeks to change the status quo; to induce an adversary to stop some action it has already taken or to otherwise change ongoing behavior. For instance, when Operation Desert Shield became Operation Desert Storm on January 17, 1991, the United States switched from a deterrence posture (preventing an Iraqi attack against Saudi Arabia) to a coercive one, namely, to use force to drive Iraqi forces out of Kuwait. An implication of this difference is that deterrence successes can be hard to ascertain, because it can be difficult to know—in the case of deterrence—if the absence of adversary action could be attributed to a successful deterrence strategy. Conversely, the invariably public way in which a state backs down in response to coercion makes cases of successful coercion easy to observe.

The second critical difference between deterrence and coercion pertains to the use of force. Deterrence is anchored in the threat—rather than the use—of force to prevent an action. In contrast, coercion often involves the application of force to change behavior. Therefore, if a threatening state finds itself employing force because the target refuses to comply, then, by definition, deterrence has failed. It is precisely in the failure of deterrence that coercion (referred to by some as “compellence”) becomes relevant. As Colin Gray notes, “[a] compellent strategy is relevant only after deterrence failed, or was not attempted explicitly.”   

Why does it matter?

Appropriate use of terminology matters. When senior leaders use phrases such as “contested deterrence” or “reestablishing deterrence,” they are confusing deterrence and coercion. Put simply, if deterrence is contested, has to be reestablished, or is in need of restoration—because the adversary does not accept the terms of the US deterrent threat—then deterrence has failed. If, as a result, the United States seeks to change the new status quo in which an adversary refuses to accept US demands, then it is pursuing coercion. In turn, if that coercive approach is ultimately successful (for instance, if the United States coerces North Korea into abandoning its nuclear-weapons program), then the United States could revert to a deterrence posture to maintain the now-acceptable status quo.

This is not merely a question of semantics over which obtuse academics engage in esoteric debates. Rather, how policymakers communicate about strategy is an important element in its success. This is especially true for strategies such as deterrence and coercion that fundamentally rest on how the target perceives the nature of the threat and what is being asked of it. As Robert Jervis notes, “[i]n the most elemental sense, deterrence depends on perceptions.” Perception could be confounded by a range of factors outside of the threatening state’s control, such as differences in strategic culture, cognitive biases, or even the sheer asymmetry of information that exists in an anarchic international environment. But, misperceptions could also result from poor communication or miscommunication (something within policymakers’ discretion), which is precisely what takes place when strategic concepts are distorted or misused.

Additionally, employing permutations of deterrence as euphemisms for coercion is not the same as strategic ambiguity: the deliberate leveraging of uncertainty to provide decision-makers with flexibility during a crisis or manipulating an adversary’s perception of risk. An example of the latter is the nature of the US defense commitment to Taiwan, or the oft-repeated statement by US presidents that they reserve the right to respond to perceived aggression or norms violations at a time, place, and manner of their choosing. In certain scenarios, strategic ambiguity can have domestic political and international benefits. However, these distortions of deterrence are not examples of strategic ambiguity.

What is the solution?

1 Clearly communicate strategy. Policymakers may find the language of deterrence to be more palatable, perhaps because deterrence is perceived as a more “legitimate” strategy than coercion. However, because both of these concepts depend on careful communication, muddying the waters will only undermine the likelihood that the United States will be successful at either type of strategic approach. Therefore, as a matter of first principles, policymakers should be more judicious in the language they employ to communicate about US strategy, especially when the adversary is the audience.

2 Reassess the use of coercive strategies. If it is indeed the case that coercion is an unpalatable strategy, it behooves policymakers to reassess the United States’ reliance on coercion to achieve policy objectives. Relatedly, if US adversaries routinely “contest” deterrence—in other words, if deterrence often fails—policymakers must systematically examine the determinates of these outcomes and incorporate lessons learned into future strategy development. This will only become more important as other states are increasingly able to pose a credible military challenge to the United States.

3 Improve education. Senior military officers frequently employ the phrases discussed in this analysis. These individuals spend a significant portion of their careers in Professional Military Education (PME) environments, particularly at the field-grade and above level, where core strategic concepts are routinely taught. Inculcating the more deliberate and careful use of terminology surrounding these concepts should be a priority of PME curricula.

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