In collective decision making, political alliances naturally arise and are critical to the negotiation processes that lead to the actual implementation of decisions. In the present context, an alliance refers simply to a group of political actors who share common, but not identical, interests against some adversary. In this paper we focus on the relationship among three constructs: the structure of an alliance, the context in which negotiations take place, and the performance of the alliance. The term alliance structure refers to the configuration of alliance members\u27 preferences as well as to their bargaining attributes. The context of negotiation refers to the rules of the bargaining game, including such factors as the structure of admissible coalitions and the range of allowable policy proposals. Alliance performance refers to the alliance\u27s effectiveness in furthering its members\u27 common objectives through the negotiation process. For example, if the space of issues can be represented in an Edgeworth box, a natural measure of alliance performance might be the location of the negotiated solution along the contract curve
