Soviet tank rolling through Tirana, 1971
The Purge of the Revisionists was the official name for the invasion of the Democratic People's Republic of Korea, the Socialist Federal Republic of Yugoslavia, and the People's Socialist Republic of Albania by the Soviet Union in 1971. Soviet Premier Vyacheslav Molotov ordered the invasions to avoid any incident similar to the one that started the Sino-Soviet War in the 1960s.
In 1971, the Soviet Union invaded Korea. Korean President Kim Il-Sung attempted to drive off the Soviets, but, contrary to the propaganda, the Red Army defeated the Korean People's Army easily.
After Korea, the Soviet Union thundered into Yugoslavia, lead by President Josip Broz Tito. Tito had renounced the Soviet Union's form of Communism, and joined the Non-Aligned movement. Tito and several of his officials were executed, and Yugoslavia was placed under military rule.
Following Yugoslavia, the Soviet Union invaded Albania, run by President Enver Hoxha. Hoxha had supported the Chinese in the Sino-Soviet War, and therefore was treated much harsher by the Red Army, who completely devastated Tirana.
After the Purge, Molotov ordered that most Soviet satellite states to incorporate themselves into the Soviet Union itself, to the shock of the West. Obedient satellites as they were, they listened, and the Soviet Union stretched from Germany to Korea