When the 70th Eurovision Song Contest begins on Saturday evening, there will be no Irish presence. That in itself is hardly unusual; in the 22 years since semi-finals were introduced, Ireland has only occasionally qualified for the grand final. This time, though, is different. There will be no “hello from Dublin” during the jury votes, no Irish televote and no broadcast of the show on Irish television.That is of course because Ireland, along with Spain, the Netherlands, Iceland and Slovenia, is boycotting this year’s competition in protest at Israel’s actions in Gaza, which have led to a humanitarian catastrophe and tens of thousands of civilian deaths. The horror of the slaughter may make the silliness of a song contest feel like a strange thing to be exercised about. But the consequences of the boycott may not end when tonight’s winner is announced.The European Broadcasting Union (EBU) has acknowledged this is the worst crisis in the contest’s history, with real financial effects. Corporate sponsors have pulled back in significant numbers, licensing fees from the boycotting countries have been lost and only 35 nations are competing in Vienna, the lowest number since 2004. What is less well known is how close things came to being far worse. According to sources cited by the Hollywood Reporter, Belgium and several Scandinavian countries were on the verge of joining the walkout before being persuaded to stay. Had they gone, there was a real possibility that this year’s event would not have happened.On the streets of Vienna this week there have been pro-Palestine protests. Four audience members were ejected from Tuesday’s semi-final for protesting during Israel’s performance.The broader question concerns what happens after Saturday. If Israel wins and hosts next year’s contest, that would almost certainly trigger a deeper and wider boycott from which the EBU might not recover. Eurovision has been a remarkably resilient symbol of post-war European friendship. Whether it can survive this particular unresolved crisis is far from clear.