On Tuesday, the Russian pavilion at the Venice Biennale was full of activity. Several pallets, piled high with cases of prosecco and a few boxes of good old English Gordon’s gin, had been delivered outside. Inside, Ensemble Toloka, a group of “young folk performers and professional researchers of Russian authentic music”, were singing, balalaikas at their feet, the first in a programme of performances staged for the preview days of the art festival.

When I sent a few seconds of footage of this to a friend, a close and critical observer of Russia who lived there until recently, the reply came quickly, a succinct review: “Ethnic shit to cover up their war crimes.” Later, I saw DJs at the decks and a handful of people dancing. At pretty much the same time, the city centre of Kramatorsk in eastern Ukraine was being bombed in broad daylight – six dead.

You have to hand it to Russia. It had much to celebrate with that prosecco. After a hiatus since 2022 it is back at the world’s most prominent art festival, where a huge central exhibition organised by an invited curator is accompanied by dozens of shows staged by countries in national pavilions. And everyone’s talking about it. Even the protests – such as Pussy Riot’s colourful intervention on Wednesday – forces the conversation on to it.

The president of the biennale, Pietrangelo Buttafuoco – a controversial rightwing intellectual appointed by Giorgia Meloni’s government – has supported Russia’s return, as well as the continued presence of Israel, despite multiple appeals and open letters, some of which have also demanded the exclusion of the US. The only thing he will veto, he has said, is any preemptive ban on participation. The stance is supposedly one of neutrality, but correspondence obtained by La Repubblica appears to show biennale managers aiding Russian participants in efforts to obtain visas, and the pavilion’s commissioner, Anastasia Karneeva, has lavishly thanked “our Italian friends” in a social-media post. In the meantime, the European Commission is investigating whether sanctions have been breached and Meloni, while distancing herself from Buttafuoco’s position, has not intervened.

In protest at Russia’s inclusion, there was no minister for the arts present at the opening of the British pavilion, this year filled with paintings and sound by Lubaina Himid. By contrast, the culture ministers of Ukraine, Poland, Moldova and the Baltic countries – those who exist in uncomfortable proximity to Russia – were very much in evidence and had a lot to say. At an event I attended on Wednesday, Poland’s culture minister, Marta Cienkowska, pointed out that “to speak the language of culture in order to drown out the reality of war” was a “classic mechanism of propaganda”. Heidy Purga, Estonia’s culture minister, accused the biennale of appearing to “yield to the aggressor”.

The biennale can often make you queasy, as geopolitics are played out through the proxy of art, and the yachts of the super-wealthy are visible evidence of ideologies far removed from those usually propounded by artists inside the exhibition spaces. But this edition is something of a different order again: it feels on the verge of collapsing in on itself, rather like the international order that it dimly reflects. Its artistic director, Koyo Kouoh, died of cancer last year leaving a void where surely her voice would now be speaking out, had she lived. Her legacy was a curatorial team to finish her work in organising the large central exhibition; and a jury, in charge of selecting artists and pavilions for awards, that she had nominated.

At the end of April the jury carved out the ethical space in which they intended to operate, amid the free-for-all that Buttafuoco had insisted upon: they published a statement saying that they would “refrain from considering those countries whose leaders are currently charged with crimes against humanity by the international criminal court”. Without naming names, that meant Russia and Israel. Immediately, they came under pressure to take back their statement, and were also threatened with legal action by the artist representing Israel. Their autonomy compromised, their choice became one of retract or resign. Under the circumstances, they took the only path they could – they resigned.

Perhaps this all seems inconsequential – artistic squabbles that have little to do with the fate of nations and people. But it really does matter – and very much so to Israel and Russia. It would be easy for them to stay away, but each nation has absolutely insisted on its presence, and with no small effort expended. Events such as the biennale offer legitimacy. They replace the thoughts of bombs and mass civilian deaths with the aura, as it might be, of Tuvan throat singing, or of the poetry of Paul Celan – though what Celan would have made of being so strongly invoked by the exhibition in this year’s Israeli pavilion is anyone’s guess.

The biennale has always reflected active choices by those in charge of it. It took decades from its foundation in 1895 for its present form – of a central exhibition accompanied by shows in nationally owned pavilions – to be developed fully. At times it has departed radically from the setup that is recognised today – in 1974, for example, the whole event was reconfigured as a months-long event in solidarity with Chile, and from then until the fall of the Berlin Wall, serious consideration was given to losing the national representations altogether, Clarissa Ricci, a historian of the biennale who teaches at the University of Bologna, told me.

Set against this unstable history, Buttafuoco’s insistence on the biennale as “a place of truce in the name of art, culture, and artistic freedom” looks less like studied neutrality and more like a pointed position. But perhaps the crucial thing to recall is that the basic structure of the biennale that we recognise today was conceived in the 1930s, under Mussolini, becoming, said Ricci, “a focus for propaganda and positioned as the peak of Italian culture”. It was to the fascists, she said, that encouraging as many different nations as possible to establish national pavilions became important. At that time, the event was frequently referred to as the “Geneva for the arts”. How fascinating, then, that Buttafuoco himself should echo this formulation, when he called the biennale “an institution that can be considered the UN of art, from which no nation can be excluded”.

• Charlotte Higgins is the Guardian’s chief culture writer