In order to accomplish what they did, Gorbachev and Yeltsin had to overcome many obstacles to change. Doing so required them to exercise leadership, which I define as a process of stretching social constraints in the pursuit of social goals. Those constraints are of several kinds: (1) organizations, institutions, and processes that structure politics and administration; (2) the material interests of individuals and groups; and (3) the identities, ideologies, and cultures of individuals and groups. Typically, in an established or entrenched system, these constraints reinforce each other. Ideologies and cultures come to justify the institutions and processes that structure both political life and the distribution of tangible rewards across the population. Those institutions and processes ensure the continuation of policies that cater to prevailing identities and that reproduce existing patterns of social and political inequality.

The Stalinist system came to be such an entrenched system, but certain features of that system did not survive for long after the death of its founder. Stalin's successors rejected a continuation of mass terror and economic austerity, rule by a despot, and perpetual confrontation with the capitalist world. Beyond that, they grappled with the challenge of reforming (Khrushchev, 1953-1964), adapting (Brezhnev, 1964–1982), or transforming (Gorbachev, 1985–1991) the Soviet system of monopolistic rule by the Communist Party- State and “anti-imperialist struggle” abroad, whereas Yeltsin (1989–1999) sought to destroy the system completely and to replace it with a workable alternative.