The disturbing recrudescence of antisemitism in Europe is not only connected with Gaza and the tragic Israeli-Palestinian conflict. Last year, I interviewed on stage Anne Applebaum, the historian, about her book, Iron Curtain. It's a magnificent account of the postwar subjugation of Eastern Europe by Soviet communism, an ideology in which antisemitism played a role.

The ailing Stalin was convinced there was a "doctors' plot" (code for a Jewish plot) to kill him. Had he not died in 1953, a further murderous purge might have been launched.

I had no conception, when Anne and I were talking, that less than 18 months later the current rulers in the Kremlin would launch aggression against a neighbouring state. But they have done, and Jews have a compelling, pragmatic interest as well as a concern for justice in what's happening in Ukraine.

There is no sign that Vladimir Putin is himself prejudiced against Jews. Yet his supporters include some of the darkest forces across Europe. It's little wonder that an editorial in Pravda after the European elections in May approvingly cited a comment by Marine Le Pen, leader of the National Front (FN) in France, that she and Putin shared "common values".

Russia has cemented its links with the FN, the far-right Freedom Party in the Netherlands, and neo-Nazi groups in Hungary, Greece and Bulgaria.

Putin's supporters include some of the darkest forces across Europe

Meanwhile, the Kremlin has lied on the international stage. Though the far right polled only two per cent of the vote in Ukraine's presidential election, the country's government is routinely castigated by Putin and his allies as neo-Nazi. It's an Orwellian tactic. The Russian invasion is simultaneously denied and depicted as defensive. The principle of linguistic homogeneity is invented to "justify" Russian annexation of Crimea, which is like saying Westminster has a justified claim to Massachusetts because most of its inhabitants speak English. The greatest doublethink of all, echoing the language of the Soviet era, is to present Russia's territorial aggrandisement as a blow against fascism.

A few months ago, I wrote in the JC about RT (formerly Russia Today), the English-language arm of Russian state broadcasting. It's a crude and often risible propaganda outlet for Putin's regime. Its "expert" interviewees include Holocaust deniers, 9/11 Truthers, UFO buffs, anti-Bilderberg conspiracy theorists and sundry other fantasists, failures, malcontents and monomaniacs. The channel is praised for its "commitment to truth and balance" - by the British National Party. On being invited to appear on RT to discuss the European economy, I unhesitatingly declined.

RT sounds and is amateurish. Yet, as with Iran's English-language Press TV, the bizarre and insanitary ideas that RT espouses are a faithful reflection of a state ideology. Timothy Snyder, the Yale historian, has written penetratingly that Putin wants Ukraine to be part of a mooted Eurasian Union, whose ideals will be very different from European standards of justice and democracy. The Eurasian scheme, espoused in the writings of the Russian political scientist Aleksandr Dugin, looks to highly unsavoury precedents. Snyder says: "Dugin's major work, The Foundations of Geopolitics, published in 1997, follows closely the ideas of Carl Schmitt, the leading Nazi political theorist."

Such ideas have gained ground under Putin and are recognisable in the regime's aggressive strategies. It's ominous. And we know, with a certainty born of historical awareness, who the supposedly alien influences are that this ideology threatens.