Donald M. Snow invites readers to consider what criteria should be evaluated when considering whether the United States should engage in military action across the globe: when its vital interests are at stake and when the endeavor can reasonably be considered feasible, what Snow refers to as the "IF factor." It is hard to justify promoting an application of American military force to a situation where its use will not succeed or where US interests are not clearly vital, but, Snow argues, that is exactly what has happened frequently since Vietnam. The book is organized into three sections, examining a historical overview of how the United States became involved in intervening in asymmetrical warfare, the problem of internal war in the developing world, and future American military involvement, particularly in conflicts in the Global South and Ukraine.