The threat to use military force is a matter that commands immediate attention from many segments of government. Karsten, Howell, and Allen systematically analyze statistically significant numbers of actual cases to discover the determinants of success or failure of the threat to employ military force. After describing their methodology, they address several questions: what are the general characteristics of the typical threat? what types of threats succeed? what threats lead to war? did threats in the prenuclear past differ in outcome from those in the nuclear present? have the United...