Recent years have seen the US, UK and other ISAF and Coalition nations enmeshed in protracted, complex and intense campaigns in Iraq and Afghanistan. Resilient and highly adaptable opponents have operated asymmetrically, and amongst the people, to negate the technological superiority of the West; counterinsurgency (COIN) has been the norm. Progress made has been hard won, consuming considerable resources and testing national will. Despite the achievement of often rapid and spectacular tactical military successes, the desired political dividends have been slower to materialise and scarcely commensurate with the investment of national blood and treasure. This has led some to question the utility of military force and the mood in several Western capitals seems increasingly wary of further stabilisation campaigns abroad. This sense of caution is reinforced by the global economic downturn and its associated fiscal challenges, which have encouraged retrenchment in public spending, especially in defence budgets. It would seem timely, given this context, to reflect upon the utility of force.Following Clausewitz's reasoning, the utility of force rests on its instrumentality in achieving a desired policy goal. This monograph contends that this involves controlling, to a sufficient degree, the adversary's policy choices, which depends on changing attitudes, and thence behavior, in a way favorable to our interests. It requires our opponents to embrace our vision of their political future: they must be convinced to accept this changed political order. The political value of armed force derives from its power to hurt (its capacity for "killing people and breaking things"); its utility is a function of how effectively this can be harnessed to influence behavior and achieve control. The ultimate expression of hard power, armed force can be used to deter, coerce or compel especially in an interstate conflict when these effects are focused on an enemy government in control of its people. In a confrontation with an enemy operating amongst the people, such as in stabilisation or COIN campaigns, where control of the people is contested and political considerations predominate, the power to hurt is diffused and attenuated, being consciously restrained by policy choices and by legal and moral norms. A greater premium is placed on persuasion over coercion. Here, activities designed to enhance legitimacy and win consent (for shorthand termed stabilization) are likely to be more effective, with the military in a subordinate role. By promoting physical security, it can create the opportunity for other instruments of power to resolve political problems; but armed force alone may resolve little.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, recognising 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.