This book examines how private security contractors or analogous historical forces affect democracies' military effectiveness and likelihood of success in warfare across different deployment scenarios, and, in doing so, illustrates both theoretical and policy-relevant implications of the increasing use of private security forces by modern democracies.

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At peak utilization, private security contractors (PSCs) constituted a larger occupying force in Iraq and Afghanistan than did U.S. troops. Yet, no book has so far assessed the impact of private security companies on military effectiveness. Filling that gap, Molly Dunigan reveals how the increasing tendency to outsource missions to PSCs has significant ramifications for both tactical and long-term strategic military effectiveness-and for the likelihood that the democracies that deploy PSCs will be victorious in warfare, both over the short- and long-term. She highlights some of the ongoing problems with deploying large numbers of private security contractors alongside the military, specifically identifying the deployment scenarios involving PSCs that are most likely to have either positive or negative implications for military effectiveness. She then provides detailed recommendations to alleviate these problems. Given the likelihood that the U.S. will continue to use PSCs in future contingencies, this book has real implications for the future of U.S. military and foreign policy.