The major European powers drafted war plans before 1914 and executed them in August 1914; none brought the expected victory by Christmas. Why? This tightly focused collection of essays by international experts in military history reassesses the war plans of 1914 in a broad diplomatic, military, and political setting for the first time in three decades. The book analyzes the war plans of Austria-Hungary, France, Germany, Great Britain, Italy, and Russia on the basis of the latest research and explores their demise in the opening months of World War I. Collectively and comparatively, these essays place contingency war planning before 1914 in the different contexts and challenges each state faced as well as into a broad European paradigm. This is the first such undertaking since Paul Kennedy’s groundbreaking War Plans of the Great Powers (1979), and the end result is breathtaking in both scope and depth of analysis.