Why do we use military force to solve our political problems? And why do our forces win the military battles, but still fail to solve those problems? It is because the force used lacks utility. From Iraq to the Balkans, and from Afghanistan to Chechnya, over the past fifteen years there has been a steady stream of military interventions that have not delivered on their promise for peace, or even political resolution. 'The utility of force' explains this anomaly at the heart of our current international system.