Declaring War directly challenges the 200-year-old belief that Congress can and should declare war. By offering a detailed analysis of the declarations of 1812, 1898 and the War Powers Resolution of 1973, the book demonstrates the extent of the organizational and moral incapacity of Congress to declare war. It invokes Carl von Clausewitz's dictum that 'war is policy' to explain why declarations of war are an integral part of war and proposes two possible remedies – a constitutional amendment or, alternatively, a significant re-organization of Congress. It offers a comprehensive historical, legal, constitutional, moral and philosophical analysis of why Congress has failed to check an imperial presidency. The book draws on Roman history and international law to clarify the form, function and language of declarations of war and John Austin's speech act theory.