『The Tragedy of Great Power Politics』要約

John J. Mearsheimer's *The Tragedy of Great Power Politics*, first published in 2001 and revised in 2014, sets out an offensive realist theory of international relations. Its central claim is that the structure of the international system—anarchy plus uncertainty about other states' intentions—compels great powers to seek maximum relative power, ideally regional hegemony, because survival can never be guaranteed. This drive, not leaders' malevolence, produces the "tragedy": security competition and war among states that would often prefer peace. Mearsheimer builds the argument through five "assumptions" about the international system (anarchy, offensive military capability, uncertainty, survival as the primary goal, and rationality) and contrasts offensive realism with defensive realism, liberalism, and constructivism. He identifies the state as the principal actor and defines power largely in material terms, especially military force, while distinguishing latent from actual power and highlighting the difficulty of measuring power through indicators such as wealth, population, and army size. The book's historical core examines the rise of great powers from 1792 to the present. Case studies cover Napoleonic France, Britain's offshore balancing and the "stopping power of water," the rise of Germany under Bismarck and its later bid for European hegemony, Japan's regional ambitions, and the Cold War superpowers. Mearsheimer argues that the United States attained regional hegemony in the Western Hemisphere and now works to prevent any peer competitor from dominating Europe or Asia—a "offshore balancer" role he also applies to Britain's past behavior. The revised edition adds chapters on China's rise, arguing that if China's economy continues to grow it will pursue regional hegemony in Asia, setting up intense security competition with the United States. The result is a systematic, pessimistic, and much-debated statement of realist international politics.