Western countries were full of communists before the liberal-tankie split. After ww2 the communists almost won the elections in Italy. It wasn't until the communists started pasting protesters with tanks that it became no longer socially acceptable to be a communist.
After the failure of world revolution only the subversion program remained. This was widely successful and is still ongoing.
A bunch of Americans went to join the communist experiment in the 20s and 30s. They saw what a disaster it was but the newspapers covered it up. The NYT famously declared that there was no famine in ukraine while millions starved. Of course the journalists were friends with Stalin.
After the failure of world revolution only the subversion program remained. This was widely successful and is still ongoing.