Europe's populist Right has had a makeover. It typically now disclaims antisemitism and expresses sympathies with Israel. It seeks the support of Jewish voters on the strength of its opposition to militant Islamism. It would be a terrible mistake for Jews to respond favourably, or even neutrally.
The issue is especially acute in France, where the National Front (FN) came first in last month's European elections, with a quarter of the vote. Jean-Marie Le Pen, the party's founder, characteristically made an antisemitic gibe in the wake of its success, only to be slapped down by Marine Le Pen, his daughter and the current party leader.
My judgment is that parties such as the FN and Geert Wilders's Freedom Party in the Netherlands (which did far less well) are never more than a step away from anti-Jewish invective.
Yet even if they genuinely managed to escape this baneful historical legacy, their outlook would still be alien to the values of European Jewry. It is true that militant Islamism is a threat to Israel and other liberal, democratic societies. Yet the populist right, in which I include Ukip, is no reliable or even sanitary ally in opposing it. Instead, its failure to distinguish Islamism from Europe's own Muslim populations is itself a crude conspiracy theory.
Those sentiments on the political fringes have been germinating for some time. I first noticed them during the Bosnian war of the 1990s. Representative Jewish organisations in the US and Europe recognised that the conflict was a war of aggression by the regime of Slobodan Milosevic in Serbia against a constitutional, multi-ethnic state. Right-wing extremists, such as the egregious Sir Alfred Sherman, maligned the Bosnian government as a front for militant Islam. You'll find a similar conspiratorial mind-set among anti-immigration campaigners such as Wilders, who depict European Muslims as a monolithic force whose high birth-rates are leading to an Islamic takeover of Western societies.
It's hysterical nonsense and it's important that such inflammatory voices don't gain traction. European Jews can recognise this type of thinking for the xenophobia that it is. What appears to be happening in European politics is what a number of pundits on the moderate left, such as David Aaronovitch and Nick Cohen, have been warning about for some time. This is a scenario where the populist right and the far left turn out to be essentially on the same side, in targeting small nations and persecuted peoples.
Where does Vladimir Putin get his principal support from in his threats against Ukraine and bizarre imperialist notions based on the linguistic homogeneity of Russian-speaking peoples? From Europe's populist right, including Ukip, and the anti-American left. By its brutality in Chechnya and hostility to the independence of Bosnia and Kosovo, the Kremlin has, over many years, stimulated rather than defused Islamist extremism. It is hardly surprising that its mouthpiece should give voice to the European and American far right.
Watch the news bulletins on RT (formerly Russia Today), the English-language propaganda station of the Putin regime. Its purported expert analysts include a motley selection of antisemitic demagogues, including outright Holocaust deniers.
Jews have a vested as well as philosophical interest in the maintenance of tolerance and democratic values.
Their continued interest is in the defeat of the populist right, and in confronting its scapegoating of minority groups and crude conspiracy theories.