I was thinking of the MolotovRibbentrop Pact, in which the two leftist tyrannies agreed not to go to war with each other.
After the pact was signed, the American Communists (and other assorted useful idiots) were all complete and total non-interventionalists, marching outside the White House to stay out of the war.
Then, when Germany invaded the USSR, in a heartbeat...literally...they switched as if on demand to agitating for the USA to get into the war.
That was what I was referring to...
American communists did what the Comintern asked them to do.
Very interesting, put motivation aside, what they called for were practically in line with American government’s strategies.