Under Brezhnev's leadership, chauvinism, a great Soviet power, gradually evolved into hegemonism. The Soviet Union not only imposed its own socialist model on the socialist countries in Eastern Europe and China, but also interfered in other countries' internal affairs, and did not hesitate to use military means to intervene. 1968, the Soviet Union invaded Czechoslovakia to suppress the Prague Spring, and Brezhnev quickly put forward the theory of limited sovereignty to defend his atrocities of invading Czechoslovakia. 1979, after the fall of pro-Su Zhengquan forces in Afghanistan, the Soviet Union invaded Afghanistan.