This book examines a topic of considerable current interest owing to the current conflicts in eastern Ukraine, Syria, and Yemen. As Tyrone Groh notes, the act of subcontracting the waging of war to a third party is suboptimal (p. 210), but, as per the title of his book, it is often the “least bad option” not only for the United States but also for allies and adversaries for the foreseeable future, providing an alternative to overt military intervention and complete disengagement (as currently demonstrated by U.S.-led coalition operations in Iraq and Syria against Daesh).

Groh approaches this topic from a policymaking perspective, outlining how the potentially negative consequences of backing proxies can be mitigated. Using the United States in Laos, apartheid South Africa in Angola, and India in Sri Lanka as case studies, he outlines four reasons for intervening in a specific conflict: achieving outright victory (“in it to win it”), waging a “holding action” to avert an enemy prevailing, “meddling,” and “feeding the chaos” (pp. 34–37). He also counsels that the successful use of nonstate proxy actors depends on three criteria: “know your enemy, but know your proxy better,” “let the proxy lead, but only so far,&rd