Russia’s war against Ukraine is an aftershock of the earthquake of 1989–91, which saw eastern Europe break free from communism’s clutches and the Soviet Union collapse. Two questions dominated European security discussions in the years that followed. The first was about how to integrate Russia into a new world order. The second was about how far, if at all, to stretch the boundaries of NATO membership into eastern Europe and the ex-Soviet states. These questions lie at the heart of M E Sarotte’s remarkable book on geopolitics in the final decade of the last century.