In the second half of Joseph Stalin’s rule, Gorlizki and Khlevniuk write, the Soviet leader became a “surprisingly disciplined delegator.” He still presided over a regime built on fear and repression, but concerns about efficiency pushed him to accord his regional party leaders greater authority. In their rigorous academic study based on a vast collection of archival documents and memoirs, the authors trace the evolution of those territorial leaders from the late 1940s to the 1970s. This choice of time frame is unusual, as it cuts across Stalin’s death, the removal of his successor Nikita Khrushchev, and the early years of Leonid Brezhnev’s rule. To the authors, however, those three decades are united by one “outstanding feature”: the gradual decline in acts of repression against members of the communist leadership. Stalin controlled local leaders through an array of institutional measures and occasional purges. Khrushchev also exercised tight controls, such as through political marginalization, but mostly dispensed with overt repression. The system opened up further under Brezhnev, who relied more on co-optation than exclusion, began to recruit regional leaders locally, and avoided the “unjustified turnover of cadres.” The territorial party leaders in Stalin’s time were “substate dictators,” who built their own fiercely coercive systems of administration. Under Brezhnev, they became “party governors,” who maintained standards of decorum in everyday conduct.