The major question addressed by this paper is: When each actor in a conflict or bargaining relationship has a power capability, how does the level of power capability in the relationship affect the likelihood of actors using coercive tactics? This paper explicates two theories that offer contradictory answers to this question. One theory, termed “deterrence,” predicts that (a) where actors have equal levels of power capability, the larger the mutual capability the lower the likelihood of using coercive tactics, and (b) conditions of unequal power capability produce more use of coercive tactics than conditions of equal power. A second theory, termed “conflict spiral,” makes the opposite predictions: Larger power capabilities increase use and relationships with equal power produce more coercive tactics than ones containing unequal power. The theoretical formulations suggest the importance of distinguishing relative power (power difference between actors) from the total power (sum of each actor’s power) in a relationship and stress the cognitive processes that mediate the relationship of power capability and power use.