Ally provocateur

The primary purpose of many alliances is to deter attacks on members of the alliance by potentially antagonistic states. Yet some alliances can increase the probability of conflict that may be initiated by alliance members. Cognizant of that possibility, states that wish to sustain peace may nevertheless intentionally form alliance commitments with revisionist leaders of other states. Faced with the partially conflicting goals of deterring antagonistic states while at the same time restraining allies, leaders often include in alliance treaties conditions that oblige allies to provide military assistance only if a member of the alliance is attacked by a state outside the alliance. However, other treaties may contain unconditional obligations to come to the defense of members of the alliance. Such alliances tend to arise from situations where some members of the alliance feel that their alliance partners need to have the flexibility even to engage in provocative behavior in order to deter the target of the alliance. Our analysis of alliance formation processes in the context of priorities that compete with each other provides a basis for two hypotheses. The first is that revisionist states with unconditional commitments from members of their alliance to come to their defense are more likely to initiate militarized conflict than states without such unconditional commitments. The second hypothesis is that revisionist states in alliances whose treaties stipulate that commitments to defend are conditional will be less likely to initiate militarized conflict than such states with allies who are committed to come to their defense without conditions. Statistical analyses of data generated with a view toward evaluations of both hypotheses (some of which provide new, more detailed categorizations of alliance treaties) suggest that they are valid.