This difference is highly significant. Communist forces across Europe adopted Antonio Gramsci's theory of cultural hegemony — "the long march through the institutions" — to outflank their enemies. Although communists could not control ministries, they colonised universities — especially departments of the humanities and social sciences. They took to the publishing houses, the newspapers, TV and magazines. They set out to shape public discourse, educate the new generations of leaders and, in typical Marxist fashion, marginalise their intellectual opponents. Even as communism collapsed in the East, its apologists in the West almost paid no moral price for covering up, condoning or defending its worst crimes. 

Not only did they make no amends for continuing to promote anti-Western foreign policy agendas, they also appropriated the liberal jargon of human rights for their own illiberal causes. In the process, they ensured that communism's ferocious past would be treated kindly.

It is time to repair the damage. Communism, after all, was a strain of totalitarianism. To recognise its viciousness is not an attempt to trivialise (or indeed overshadow) the monstrosity of Nazi crimes. The gulag and the Holocaust should never be made to compete for first prize in the galaxy of evil. But they both belong there, because of the horrors committed in the name of ideology and the number of their victims. 

Likewise, our free societies should become immune to the temptation of left-wing totalitarianism through the same processes that immunised us from its fascist next of kin. Museums should be built in memory of the millions of victims of communism, and archives and foundations should shed historical light on the terrible injustices committed in its name. Reparations should be made where possible. Living remnants of that repression should be tried and punished, at least symbolically. The leaders responsible for communist crimes should not be immortalised through streets and monuments. And programmes to educate the new generations in the crimes of communism should be introduced in schools.

Meanwhile, the apologists of left-wing totalitarianism remain entrenched at the centre of intellectual and cultural life. The best antidote to their pernicious influence is to expose the evil premises of their world view and hold them properly accountable for their moral bankruptcy.