On the debate over whether or not arms transfers increase or deter the chances of war, Cassady B. Craft offers a balanced assessment of the effect of arms transfers on war involvement and outcomes. He considers correlations at the state and global level, supplier and recipient relationships, and the extent of the relationship in the perceptions of individual leaders. This is the first study to examine the influence of arms transfers on combined interstate and civil wars. Drawing on a variety of theories and quantitative methods, including force-on-force attrition models, it uses innovative techniques that have the potential to change the way analysts weigh the impact of weapons sales. This book will provide both analysts and policymakers with a comprehensive examination of the various tradeoffs between weapons sales and the probability of conflict.