Compellence

Compellence is a form of coercion that attempts to get an actor (such as a state) to change its behavior through threats to use force or the actual use of limited force. Compellence can be more clearly described as "a political-diplomatic strategy that aims to influence an adversary's will or incentive structure. It is a strategy that combines threats of force, and, if necessary, the limited and selective use of force in discrete and controlled increments, in a bargaining strategy that includes positive inducements. The aim is to induce an adversary to comply with one's demands, or to negotiate the most favorable compromise possible, while simultaneously managing the crisis to prevent unwanted military escalation."

As distinguished from deterrence theory, which is a strategy aimed at maintaining the status quo (dissuading adversaries from undertaking an action), compellence entails efforts to change the status quo (persuading an opponent to change their behavior). Compellence has been characterized as harder to successfully implement than deterrence. Compellence can entail strategies to punish an adversary, raise the risk for an adversary, or deny the adversary from achieving their objectives. Successful instances of compellence in one case may have a deterrent effect on other states, whereas a reputation for a lack of resolve may undermine general deterrence and future compellence.

Compellence is one form of coercion. Some scholars conflate coercion and compellence.

Compellence typically entails efforts to change the decision calculus of an adversary by manipulating the costs and benefits of certain actions. Daniel Byman and Matthew Waxman define compellence as "getting the adversary to act a certain way via anything short of brute force; the adversary must still have the capacity of organized violence but choose not to exercise it". Coercion strategy "relies on the threat of future military force to influence an adversary's decision making but may also include limited uses of actual force". Joseph Nye emphasizes that compellence depends upon the credibility and the cost of the threat. "If a threat is not credible, it may fail to produce acceptance and it may lead to costs to the reputation of the coercing state. In general, threats are costly when they fail, not only in encouraging resistance in the target, but also in negatively influencing third parties observing the outcome."

The term deterrence is differentiated from compellence. In his influential work, Arms and Influence, Thomas Schelling puts forth a general concept of coercion theory as it emerges beyond deterrence. According to Schelling, deterrence is merely a passive threat aimed at keeping an adversary from acting. It is only a threat. "Initiative is placed on the opponent to take the first action triggering a response from the coercer." Schelling believes that deterrence does not present "a comprehensive picture of coercion, leading Schelling to introduce the concept of compellence".

'Compellence', in contrast to 'deterrence', shifts the initiative for the first action to the coercer. While deterrence means waiting passively in hope of not seeing a response, compellence is active, thereby, "inducing his withdrawal, or his acquiescence, or his collaboration by an action that threatens to hurt". When differentiating between deterrence and compellence, deterrence can be described as "drawing a line in the sand" and acting only if the adversary crosses it; in contrast, compellence "requires that the punishment be administered until the other acts rather than if he acts" as in deterrence. "Coercion composed of both compellence and deterrence is about action and inaction." Alexander L. George, a scholar of international relations and former professor of political science at Stanford University, was a pioneer in the field of political psychology. Like Schelling before him, Alexander George worked to create a diplomatic strategy of coercion; his was the theory of compellence. Unlike Schelling, George's theory of 'compellence' is different than Schelling's 'coercive warfare', in that he believed that compellence was "a subset of coercion and compellence". He viewed it as encompassing "defensive" compellent actions only: to force a target to stop or reverse action already taken, rather than an offensive goal of forcing them to do something ... Compellence essentially is the embodiment of a "carrot and stick" philosophy: motivation is used to induce a target to submit to your wishes, while appearing threatening at the same time".

According to Alexander George, compellence seeks to achieve three objectives. First, it attempts to persuade an adversary to turn away from its goal. Second, it seeks to convince an adversary to reverse an action already taken. Third, it may persuade an adversary to make "fundamental changes in its government". When constructing a compellence strategy, policymakers must consider certain variables or "empty boxes" that must be filled. They must decide "what to demand of the opponent; whether and how to create a sense of urgency for compliance with demand; whether and what kind of punishment to threaten for noncompliance; and whether to rely solely on the threat of punishment or also to offer conditional inducements of a positive character to secure acceptance of the demand".

Alexander George developed a framework in which a number of "variants" or methods of using compellence could be deployed to achieve these objectives. These variants include the following: