Why do some coercive demands succeed but others fail? A dominant paradigm explains coercive outcomes by pointing to the credibility and severity of threats. The concept of coercive assurance is an understudied type of commitment problem in the coercion literature. It suggests that a coercer must assure its target that its threats are conditional on the target's behavior. Many scholars overlook coercive assurance, in part because they assume it is automatic. But assurance is a crucial component of any coercive process. Even highly credible and severe threats can fail when the coercer's assurance is not credible. A novel theory, the assurance dilemma, helps to answer the following questions: Why do targets of coercion fear unconditional pain? Why do coercers punish after receiving compliance? What is the relationship between threats and assurances in coercion? The actions that a coercer can take to bolster the credibility of a threat undermine the credibility of its assurance that it will not punish the target. Targets fear that punishment may be unavoidable and thus look for assuring signals before ceding to the coercer's demands. The case of coercive bargaining over the Iranian nuclear program demonstrates the logic and effectiveness of the use of assurance.

Conventional wisdom sees nuclear brinkmanship and Thomas Schelling's pathbreaking “threat that leaves something to chance” as a solution to the problem of agency in coercion. If leaders cannot credibly threaten to start a nuclear war, perhaps they can at least introduce uncertainty by signaling that the decision is out of their hands. It is not so easy to remove humans from crisis decision-making, however. Often in cases of nuclear brinkmanship, a human being retains a choice about whether to escalate. When two sides engage in rational decision-making, the chance of strategic nuclear exchange should be zero. Scholars have explained how risks associated with accidents, false warnings, and pre-delegation creep into nuclear crises. An investigation of how chance can still produce leverage while leaders retain a choice over whether and when to escalate adds to this scholarship. There remains an element of choice in chance. For a complete understanding of nuclear brinkmanship, psychology and emotion must be added to the analysis to explain how leaders make decisions under pressure. Human emotions can introduce chance into bargaining in ways that contradict the expectations of the rational cost-benefit assumptions that undergird deterrence theory. Three mechanisms of nuclear brinkmanship—accidents, self-control, and control of others—illustrate how a loss of control over the use of nuclear weapons is not a necessary element of the threat that leaves something to chance. Choice does not have to be eliminated for a risk of catastrophic destruction to remain.