Bottles of champagne were popping in the arrivals hall at Ben Gurion airport. A group of teenage boys, all wearing white kippot, were dancing in circles while singing Am Yisrael Chai— a song which traditionally expresses the survival of the Jewish people against all odds. Around them, crowds were whistling and cheering.

The return of a squad of military heroes, who had just performed an act of extraordinary bravery? Perhaps a group who had miraculously survived a deadly assault by terrorists?

Not exactly.

The boys in question had just returned from Cyprus, where they had been accused of raping a British tourist. While they were cleared of any legal wrongdoing, they had apparently filmed her —against her will — having consensual sex. They then kicked her out of their room and released the video online.

Now that she had recanted the rape charge the boys vowed to sue her. “The Brit is a whore!” they shouted, in between rounds of Am Yisrael Chai. And their parents — and many supporters — swore that the children were angels and would never touch a girl against her will. Not only were they defending their errant sons, they were arguably stopping them from taking responsibility for their actions.

A large proportion of Israelis were disgusted by this spectacle, and went on social media to say so. But what about the rest? What could possibly explain such moral blindness — such insistence, against all the evidence, that these boys were the salt of the earth, rather than scumbags who treated a woman like a piece of meat and then deliberately humiliated her?

Some have argued that this is a classic case of “toxic masculinity”, where boys are encouraged to engage in harmful, aggressive behaviours some people associate with men.

Tribal loyalty may also be part of the story. But the deeper answer lies in another shameful episode which engulfed Israel recently. Back in 2016, a soldier named Elor Azaria was accused of shooting to death a terrorist in Hebron, who had already been neutralised and was lying wounded on the ground.

This went against the army’s ethical code, and is — again— morally indefensible. (In Azaria’s case, it was legally indefensible as well; he eventually went to jail.) Still, not only did his family and tens of thousands of supporters stand by his side, they mounted an aggressive, practically hysterical campaign in which he was portrayed as nothing less than a full-blown hero, “everybody’s son” — yet more salt of the earth.

The reaction to both incidents was virtually identical, and they stem from the same place.

In a society under siege and a country in perpetual war mode, the “them versus us” mentality is strong. And, increasingly, there is little room for nuance. On both sides, “Us” tends to be perceived as good, noble, motivated by pure intentions, on the right side of history, an underdog. All too often, “Them” — the “other” — barely register as real people.

In Azaria’s military case this was self-evident. To his defenders, a soldier defending the Jewish people equalled good; a terrorist equalled disposable, whatever the circumstances.

But much the same mentality and instincts seemed to be at work with the Cyprus boys-nearly-men. Why wouldn’t it be? They emerge from the exact same culture —one which tells them, again and again, that the world is against them and that they are on the side of the righteous.

“You are on the wrong side” does not compute.

This form of indoctrination is in no way just an Israeli problem, nor does it occur only on the right. There is a strong example right here in the UK, where large swathes of Labour supporters seem convinced that party members are incapable of being racist, because they have been told again and again that they are on the side of the angels, the poor, the downtrodden. Bound by socialist ideology rather than nationalism, and feeling under siege themselves, they show the same moral blindness as the Israelis supporting Elor Azaria and the Cyprus group (though they would certainly resent the comparison).

Extremism, whatever the cause, has many characteristics in common, not least absolute moral certainty — to a fault. Given the current political climate, get used to these moral gymnastics, where seemingly normal people defend the indefensible and excuse the inexcusable.