This book examines the purpose and dominant characteristics of military force and highlights the conditions that must obtain if military success is to be translated into political advantage in the contemporary operating environment. It uses recent British experience in Iraq to illustrate some of the challenges involved. It concludes that despite the complexity and frustrations of Iraq and Afghanistan, armed force retains utility in the contemporary operational environment, as long as certain conditions are met. These are that the missions allocated to the military are appropriate, recognizing the limitations of force; are adequately resourced; are properly integrated with other instruments of national power; and are underwritten with the requisite political commitment to sustain them over time.