Furr has been described by historians John Earl Haynes and Harvey Klehr as a historical revisionist who "lauded creation of Communist regimes" in Europe and Asia because "millions of workers are exploited, murdered, tortured, oppressed by capitalism". Writing for The Daily Beast, Cathy Young described him as "a 'revisionist' on a career-long quest to exonerate Stalin". Furr believes that the Katyn massacre was committed by Nazis rather than by the NKVD. He has also claimed that the Soviet Union did not invade Poland in 1939 and that all defendants of the Moscow Trials were guilty as charged. According to Russian government-owned news agencySputnik, Furr believes that "the US and NATO have been by far the most aggressive and murderous power in the world since WW2" while "the USSR never did anything remotely comparable" to the crimes by the West. In a CounterPunch article, Furr argues that "there has never been any evidence of a 'Holodomor' or 'deliberate famine,' and there is none today. The 'Holodomor' fiction was invented by Ukrainian Nazi collaborators who found havens in Western Europe, Canada, and the USA after the war". Furr's book Khrushchev Lied attacked the speech given by Nikita Khrushchev called "On the Cult of Personality and Its Consequences", more commonly referred to in the West as the "Secret Speech". According to a review of the book by Sven-Eric Holmstrom in the Journal of the Research Group on Socialism and Democracy, "Furr identifies 61 allegations in Khrushchev’s speech. He concludes that, with only one minor exception, every one of them is demonstrably false. In essence Furr claims to have proven that this 'speech of the century' is a fraud from beginning to end". According to British journalistJohn O'Sullivan writing for National Review, Furr is "a 'historian' who denies that Stalin committed any crimes at all. Revisionist historians nostalgic for 'really existing socialism' have long sought to minimize the number of Stalin's victims and the scale of Soviet crimes. But the extravagance of Furr's claims — every accusation against Stalin false! — made it hard to take them seriously. They amount less to revisionism than to outright denial of historical reality". Conservative writer David Horowitz listed Furr as one of the "" for "venting" his Stalinist and anti-American "political passions on his helpless students" by claiming that the United States got what it deserved on September 11 and misinforming his students by claims like the United States being behind the attempted assassination of Pope John Paul II. Furr has been also been accused of academic malpractice by Marxist-turned conservative Ronald Radosh. During a public debate in a university campus, Furr said that "I have yet to find one crime — yet to find one crime — that Stalin committed. I know they all say he killed 20, 30, 40 million people — it is bulls–t. Goebbels said that the Big Lie is successful and this is the Big Lie: that the Communists — that Stalin killed millions of people and that socialism is no good". Furr referred to Nazi propaganda because a mediator of the discussion suggested that Furr was using tactics invented by Joseph Goebbels.
