The Israeli prime minister counts himself a member of the club of strongmen who disdain the “l(fā)iberal” in liberal democracy. Mr Netanyahu, like Mr Orban, is a firm admirer of US President Donald Trump. Mr Orban seems to imagine himself a pocket-sized version of Russia’s President Vladimir Putin. His ruling Fidesz party has removed constitutional checks and balances and seized control of state media and the judiciary. Mr Orban champions illiberalism over the pluralist values of the EU — even as he holds out a hand for hefty aid cheques from Brussels.

Last month, the Hungarian prime minister praised Miklos Horthy, the nationalist leader who colluded during the second world war in the dispatch to Nazi death camps of Hungarian Jews. He counted Horthy among the country’s “exceptional statesmen” — drawing criticism from Jewish groups. The US Holocaust Memorial Museum said such statements created the impression that the government “believes that anti-Semitism, racial and religious prejudice, and genocide merit praise rather than universal condemnation”.

Peter Szijjarto, the foreign minister, said Mr Orban accepted that Horthy’s rule had also included some “very negative periods”. This was enough to reassure Mr Netanyahu. Others might view the murder of 565,000 Jews from Hungary as more than a “negative period”.

The state-funded attacks on Mr Soros began with a law to close Budapest’s central European University, founded by the American-Hungarian investor to nurture freedom and democracy after the collapse of communism. Mr Orban, like all ethnic nationalists, has a keen eye for “foreign” enemies.

The country is now plastered in posters denouncing Mr Soros for challenging Mr Orban’s hardline response to the Middle East refugee crisis. Mr Soros is accused of backing “illegal” immigration. Yet he has called for legal routes for those caught up in the worst of the region’s violence and for EU-wide quota arrangements to share the burden.

Mr Orban is careless of such distinctions. Last year he led an Islamophobic backlash against the refugees, saying they would steal the jobs of Hungarians and infiltrate terrorists. Hungary has refused to accept any EU quota.

Dominated by a huge image of a smiling Mr Soros, the posters exhort Hungarians not to let him “have the last laugh”. Some have been defaced with more overtly racist slogans — the imagery recalls the anti-Semitism that says Jews laugh at the fate of their supposed victims. Mr Soros survived the Holocaust by hiding from the Nazis in Budapest before fleeing to the US.

Andras Heisler, the president of the Federation of Hungarian Jewish Communities, says the billboards carry “toxic messages” from those times. Yossi Amrani, Israel’s ambassador in Budapest, has voiced the same fear, calling for them to be removed lest they sow “hatred and fear”.

Careful though it has been publicly to condemn anti-Semitism, Mr Orban’s government has been permissive of the xenophobia preached by the neo-Nazi Jobbik party. Jobbik leaders have suggested registration of the nation’s Jews. Opinion polls suggest the party is backed by a fifth of voters. Mr Orban, facing an election next year, does not want to be outflanked on the right.

In the circumstances it is more than puzzling that Mr Netanyahu should go ahead with the visit. True, Mr Soros has opposed the Israeli leader’s hawkish stance on peace with Palestinians — prompting the Israeli foreign ministry to accuse him of undermining “democratically elected governments”. But rising anti-Semitism in central Europe — a trend not confined to Hungary — should surely ring loud alarm bells.

In any event, Mr Netanyahu’s relaxed attitude should not be taken by Europeans as exculpation. Rising populism has exhumed the continent’s demons. Poland’s government, run by the rightwing strongman Jaroslaw Kaczynski, seeks out its own ethnic enemies as it dismantles democratic safeguards. Warsaw now airbrushes from history the role played by Polish collaborators in the murder of Jews. Like Hungary, Poland is a big beneficiary of EU financial assistance. Christian nationalism, casting Islam as a civilisational threat, is on the march also in Slovakia and the Czech Republic.