First published in 1988, this historical and quantitative analysis of war defines systemic world wars as conflicts of wide scope and intensity, which leave profound historical legacies in their wake. Manus Midlarsky examines various possible explanations for the onset of such past wars as the Peloponnesian War, the Thirty Years' War, and World Wars I and II. Midlarsky develops his basic theory of systemic war, outlining the reasons for the absence of wars of this magnitude and describing the violations of certain structural conditions that are associated with the onset of world war. A timely and relevant reissue, this insightful analysis will be of particular value to those with an interest in International Relations, War and Peace Studies, Military History, and Security Studies.