At this time the Soviet Union benefited from détente (a relaxation of tensions and improved relationships between the Soviet Union and the United States). In the 1970's these two countries signed SALT I and SALT II (Strategic Arms Limitation Treaty). They also signed the Anti-Ballistic Missile (ABM) Treaty which limited the nuclear arms race against each other.
When Brezhnev came to power him and the Soviet leaders relaxed rule on Western music, dress and art which allowed more access to these things. The leaders allowed this to happen because they felt more secure in the world.
The leaders of the Soviet Union started to ease rule on culture in the Soviet.
When Stalin died, the Soviet satellite states in Eastern Europe wanted to pursue a new course for their governments. The Soviet Union made it clear that they were not allowed to become independent of Soviet power. The satellite states collectivized agriculture (organize on the basis of ownership of the people and state, and no one can own private property), eliminate all noncommunist parties, and set up institutions of repression. (Secret police and military force). In 1956, Poland started to protest. In Hungary protests erupted because they wanted the same reforms as in Poland.