> which they used to help establish friendly dictatorships across Eurasia, from East Germany, to China (simultaneously, the US put an arms embargo on the legitimate government who were fighting the communists)

How did Russia establish a friendly communist government in Hungary in 1919 when it had no troops there? Actually England armed the Romanians to overthrow the Hungarian communist government.

Of course, the US, England etc. invaded Russia and fought the Red Army during/after World War I with the Polar Bear expedition etc.

Stalin dissolved the Comintern during World War II, and the Communist Party USA dissolved as a political party as well at that time.

With Albania and Yugoslavia, Red Army troops passed quickly through a small corner of Yugoslavia and offered little help to Tito.

Insofar as China, the Soviet ambassador as far as I know was the only one who accompanied Chiang Kai Shek to Taiwan. Mao took China back from the Japanese with little help.

Greece probably would have become communist after World War II, but for the Truman doctrine and US involvement, Russia did not get involved at all.

Moscow's lack of support helped in the breaks in relations - with Yugoslavia, Albania and the Sino-Soviet split.

What you're saying is rather ahistorical.