The title of Peter Clarke’s latest book, The Locomotive of War: Money, Empire, Power, and Guilt, is taken from the famous quote attributed to Leon Trotsky, “War is the locomotive of history.” Throughout this enjoyable and interesting book, the author considers the ramifications of the First World War as well as the role of Gladstonian Liberalism in Anglo-American decision-making as related to the conflict. Clarke (Cambridge and author of Mr. Churchill’s Profession) surveys the origins of the war, the financing of the war, and the Treaty of Versailles (including War Guilt, Reparations, and the Hang the Kaiser). He contends that the “moralization” of the origins of the war led to the “moralization” of the peace terms. The leading figures considered in the book are David Lloyd-George, Woodrow Wilson, and John Maynard Keynes, while Winston Churchill plays a more limited role in the study.