: In 1988, Gorbachev withdrew troops from Afghanistan and signaled that the USSR would no longer intervene in the internal affairs of its allies.

Formulated in 1968, this doctrine held that when forces "hostile to socialism" attempted to turn a socialist country toward capitalism, it became a common problem and concern for all socialist countries.

: Early Soviet theory emphasized "proletarian internationalism," suggesting workers' interests across borders were more vital than national boundaries.

The doctrine transformed Eastern Europe into a sphere where independence was strictly monitored.

: Moscow reserved the sole right to define what constituted "true socialism" and what was a "capitalist threat". 📉 Demise: The "Sinatra Doctrine"

The policy remained in effect until the late 1980s when Mikhail Gorbachev introduced "New Thinking" in foreign policy.

: Soviet officials jokingly referred to this new policy as the Sinatra Doctrine —allowing Eastern European states to do things "their way".