Back when they were the USSR, their thinly-veiled proxies (such as [1]) murdered and blew things up in the West into the 1980s. The radical left and radical right were equal-opportunity puppets.

I have a pet conjecture that they might have actually murdered FDR too, though he was so frail that it probably only took a 'pat on the back' in Yalta [4] (unlike their first try on Navalny [2] and Yushchenko [3].) Unlucky for them, Truman ended up being a much tougher rival than FDR would have been, IMO.

[1] https://en.wikipedia.org/wiki/Red_Army_Faction

[2] https://en.wikipedia.org/wiki/Poisoning_of_Alexei_Navalny

[3] https://en.wikipedia.org/wiki/Viktor_Yushchenko

[4] https://en.wikipedia.org/wiki/Yalta_Conference