The talk is of historic relationships rent asunder, of great alliances torn apart. You think I’m talking about Brexit, right? Think again.

What I have in mind is a different relationship, one that should be unbreakably strong: the bond between diaspora Jews and Israel. Start with a number you may have missed in the coverage of this month’s US midterm elections. It is 79%: the proportion of US Jews that voted for Democrats, and against Donald Trump. According to the Pew Research Center, that makes Jews the most consistently pro-Democrat, anti-Trump of all America’s religious groups. Indeed, it makes Jews the most solid voting bloc by faith for any party. Even white, born-again evangelical Christians — as staunchly Trumpian a group as you could name — could not match the Jewish level of commitment: only 75 per cent of them voted Republican.

For those who have long drawn pride in Jews’ historic attachment to progress, that 79% figure is welcome. (It’s also rather handy evidence to put before Pete Willsman, the Labour apparatchik who famously told his fellow members of the party’s national executive committee that they need not listen to Jewish concerns about antisemitism, since we were a bunch of “Trump fanatics.”)

But here’s the problem. Pew also measures global attitudes to the US and its president. Last month, it found that Trump is reviled across the planet, with rock bottom numbers everywhere you look. Everywhere, that is, except Israel. There, Trump’s positive rating jumped from 56% in 2017 to 69% now, a spike Pew attributes to Trump’s move of the US embassy from Tel Aviv to Jerusalem.

Those numbers tell a stark story, one that goes deeper than a difference of opinion over the US president. It suggests Israelis and diaspora Jews have developed fundamentally different ways of seeing the world.

Proof came in brutal fashion at the end of last month, after 11 Jews were gunned down while at prayer at the Tree of Life synagogue in Pittsburgh. You might think such an event would trigger a rare outbreak of Jewish unity, US Jews and Israelis coming together to share a moment of common heartbreak. But that’s not how it played out.

On the ground, many — not all — Jews wanted Donald Trump to stay well away from their stricken community. More than 70,000 people signed an open letter urging Trump not to visit Pittsburgh and, when he did come, he was greeted with a protest several hundred strong.

Some of that was driven by fury at how Trump had reacted to the massacre: his first, unscripted remarks repeatedly noted the Tree of Life’s past refusal to station armed guards inside the shul, heavily implying that it was their own fault. Several times he praised the local police, but offered no words of sympathy for the community itself — only criticism. Later, on the very day of the shooting, he addressed a campaign rally. That was controversial in itself, and Trump joked that maybe he should have cancelled. Not because the most lethal antisemitic incident in US history had taken place that day, but because, in talking to reporters about it outdoors earlier, his hair had got blown about. For that reason, he mused to the crowd, perhaps he should have called off “this arrangement because I have a bad hair day.”

Other US Jews had a more basic grievance. They held Trump indirectly responsible for a crazed white supremacist running into a synagogue shouting “All Jews must die.” For what had been a staple of the president’s campaign speeches, but his attacks on shadowy, powerful “globalists” and on George Soros, now less a man than a trope — both terms instantly understood by antisemites as codewords for Jews? Wasn’t it obvious that Trump had fomented the atmosphere in which the Pittsburgh killer had struck?

Not to the government of Israel, it wasn’t. Naftali Bennett flew to Pittsburgh as Israel’s representative, and he was quick to say it was “unfair, it’s wrong” to blame Trump. Trump was a friend of Israel and that was the important thing.

This is becoming a perennial argument, rehearsed recently, for example, over Hungary’s Viktor Orban. The community on the ground, in Budapest, felt threatened by Orban’s re-election campaign — again, targeting Soros — but Israel wouldn’t hear of it. When the Israeli ambassador to Hungary took the community’s side, and condemned Orban, Jerusalem moved swiftly to “clarify” his remarks. Orban is warm to Bibi Netanyahu, so that’s all that counts.

There is a values gap here. It seems the Pittsburgh killer targeted the Tree of Life synagogue in part because it had given support to refugees, which fuelled his crazed belief that Jews are bent on diluting the white race. Naturally, the ultra-nationalist Bennett did not mention any of that when he got to Pittsburgh and nor did Netanyahu, who has tweeted his enthusiastic support for Trump and his border wall. Little wonder that Haaretz’s Chemi Shalev writes that, “Israelis are from Mars and American Jews are from Venus.”

Of course, both diaspora Jews and Israelis will always speak of a “deep and special relationship”, just like Theresa May and Donald Tusk. But the reality is that, under the surface, we are drifting ever further apart.

Jonathan Freedland is a columnist for the Guardian