‘The final phase, 1980–90’ recounts how the late 1980s witnessed the most momentous changes in the overall structure of world politics since the 1940s. Why did the Cold War end when it did? How does one make sense of a decade that opens with a rapidly intensifying Cold War and closes with a historic Soviet–American rapprochement, unprecedented arms control agreements, the withdrawal of Soviet power from Eastern Europe, Afghanistan, and elsewhere, and the peaceful reunification of Germany? These questions can be looked at by examining the Cold War’s final phase, including Mikhail S. Gorbachev’s accession as the general secretary of the Soviet Communist Party and the demolition of the Berlin Wall.