Parenti gets it right in Blackshirts & Reds:

For decades, many left-leaning writers and speakers in the United States have felt obliged to establish their credibility by indulging in anticommunist and anti-Soviet genuflection, seemingly unable to give a talk or write an article or book review on whatever political subject without injecting some anti-Red sideswipe. The intent was, and still is, to distance themselves from the Marxist-Leninist Left.

Adam Hochschild, a liberal writer and publisher, warned those on the Left who might be lackadaisical about condemning existing communist societies that they “weaken their credibility” {Guardian, 5/23/84). In other words, to be credible opponents of the cold war, we first had to join in cold war condemnations of communist societies.

Was pretty funny reading King Leopold's Ghost and noticing all the anti-Soviet shit and then reading Blackshirts & Reds and seeing Hochschild get called out by name