>I'm curious about how American leftists reacted to the Vietnamese
>intervention in Cambodia, the Soviet intervention in Afghanistan,
>etc. at the time when they happened.
Dunno about VN in Cambodia, but the only left group in the U.S. to support the Soviet intervention (or invasion, depending on your proclivities) was the Spartacist League. Everyone else was critical. The Sparts have reprinted some of their commentaries from then in an I-told-you-so manner.
Doug