In brief, the right to be sued is the power to accept a commitment. In the commitments discussed up to this point, it was essential that one’s adversary (or “partner,” however we wish to describe him) not have the power to release one from the commitment; the commitment was, in effect, to some third party, real or fictitious. The promise is a commitment to the second party in the bargain and is required whenever the final action of one or of each is outside the other’s control. It is required whenever an agreement leaves any incentive to cheat.

Thomas C. Schelling, The Strategy of Conflict, loc. 114