This chapter offers thoughts on the relationship between deterrence and escalation, on the one hand, and the broad topic of negotiation, on the other. The overall relationship is familiar – negotiations frequently take place in the shadow of deterrence, and negotiations also occur directly via deterrence efforts or other coercive steps. Escalation is one possible cause or result of deterrence efforts. It is also something deterrence is often used to prevent, frequently to make progress toward or in negotiations.
Before tackling this broad subject, however, several general comments must be made about deterrence, particularly those aspects relevant to the chapter topic. Deterrence is an effort to prevent someone from doing something unacceptable by threatening a harmful response if they do. Technically, the unacceptable action can be almost anything, and the painful response might involve all sorts of harm; but in security studies, the emphasis in the definition is normally on preventing someone from attacking with force by threatening a nasty military response. It is customary to distinguish deterrence by retaliation from deterrence by defense. Though both retaliation and defense can inflict harm after an attack, the use of threats of retaliation alone is considered the purer form. A party might use defenses primarily for protection and simply gain some deterrence as a bonus, but with a retaliatory capacity only, it is entirely dependent on deterrence to keep safe and is otherwise unprotected.