Original sentence: Another explanation is that the West had already problems enough to keep it busy, in part because of the disruptive leftist agitation of May 1968, and the Vietnam War.Criticism from the democratic countries was quite muted.However, it was still seen by the Soviet leadership as a threat to their hegemony over other Eastern European states.Leftist writers such as Tariq Ali argue that this was because the western states saw the humane and democratic socialism espoused by the Czechoslovaks as being an even greater threat to capitalism than Soviet communism, which had largely been discredited by 1968.Perhaps a more convincing argument than either of the above is that the reality of nuclear standoff in the Cold War meant the western countries were in no position to challenge Soviet military force in Eastern Europe.This doctrine remained in force until it was replaced by the Sinatra Doctrine under Mikhail Gorbachev in the 1980s.Unlike the other countries of Eastern Europe the communist take-over in Czechoslovakia in 1948 - while as brutal as elsewhere - was a genuine popular movement and reform in the country did not lead to the convulsions seen in Hungary
Edited sentence: However, it was still seen by the Soviet leadership as a threat to their hegemony over other states of Eastern Bloc.Only vocal criticism from the democratic countries followed - the reality of nuclear standoff in the Cold War meant the western countries were in no position to challenge Soviet military force in Central Europe.The occupation was followed by large wave of emigration (estimated about 100,000), typically of highly qualified people.This doctrine remained in force until it was replaced by the "Sinatra Doctrine" under Mikhail Gorbachev in the 1980s.Unlike the other countries of Central and Eastern Europe the communist take-over in Czechoslovakia in 1948 - while as brutal as elsewhere - was a genuine popular movement and reform in the country did not lead to the convulsions seen in Hungary