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In many ways the policy of Japan is the weathervane of international politics. Even before military aggression became the modern world’s favorite modus operandi, Japan put it to use in 1894–95 against China and again in 1904–05 against Russia, and even its military tactics foreshadowed those that combatants later employed in the First World War. Once again in the 1930s, by the time Hitler’s steamroller got moving, and even before Italy invaded Ethiopia, Japan had already seized and occupied Manchuria. Then, after its defeat in World War II, Japan led a trend in the opposite direction. In the 1970s and 1980s, long before the Johnny-come-lately Great Powers, the Soviet Union and United States, had understood the revolutionary new trends in world politics, Tokyo had already put...