Why have some interstate crises escalated to war when other have not? Are there patterns of behavior that war-prone disputes share in common? These are some of the questions considered by Russell Leng as he examines the behavior of nations in forty militarised crises occurring between 1816 and 1980. Leng considers the conditions under which crises are more or less likely to escalate to war or be resolved peacefully and compares the descriptive and prescriptive validity of two competing perspectives on conflict behavior: classical realism and the psychological approaches of behavioral scientists. The author concludes that elements of both realist and psychological perspectives are necessary for an adequate understanding of interstate crisis behavior and that the most effective approach to crisis bargaining combines each perspective in a firm-but-flexible 'reciprocating' strategy. The epilogue presents a provocative critique of the bargaining strategies pursued by the United States and Iraq during the Gulf Crisis of 1990–1991.