Tuesday 7 April. It was an evening much like any other. At 9pm French TV channels were airing a game show, a repeat of Kitchen Nightmares and, on the Franco-German channel Arte, a documentary soberly titled Europe in Putin’s Grip? (since tracking the Russian threat is its favourite occupation).

The day itself, however, had been far from ordinary. A few hours earlier, Donald Trump had posted an exceptionally violent warning on Truth Social: ‘A whole civilisation will die tonight, never to be brought back again.’ The civilisation he was referring to was that of Iran and its 90 million people. He even specified the timing of this pre-announced genocide: 8pm in Washington. Prime time.

Words can be criminal. At Nuremberg in 1946 the Nazi publisher and propagandist Julius Streicher – who had not himself carried out or ordered any killings – was convicted of crimes against humanity on the grounds that he had incited the extermination of the Jews. Since then, the 1948 Convention on the Prevention and Punishment of the Crime of Genocide has prohibited ‘direct and public incitement to commit genocide’. And international humanitarian law forbids ‘acts or threats of violence the primary purpose of which is to spread terror among the civilian population’.

As the philosopher Mathias Risse recently wrote, this is ‘one of the foundational achievements of the post-war legal order. It was built on the recognition that the language of civilisational destruction is not merely the symptom of atrocity but one of its instruments’ (1).

European leaders know how to take words seriously – when it suits them. Fifteen years ago, they cited statements by Muammar Gaddafi and his son, who threatened to ‘cleanse Libya house by house’ and let ‘rivers of blood’ flow, to justify military intervention there. Now Donald Trump can proclaim a genocide – the most serious crime under international law – and everyone carries on as normal. China called for ‘de-escalation’. European Commission president Ursula von der Leyen and the EU’s chief diplomat Kaja Kallas said nothing.

Trump’s behaviour, France’s foreign minister, Jean-Noël Barrot, blandly observed, ‘is a source of very great unpredictability, of very great uncertainty, which have become part of our daily lives’. Former US president Barack Obama, meanwhile, devoted his only tweet of the day to a university basketball team’s win.

No one demanded accountability or sanctions, or even saw fit to name Trump’s comments for what they are. Throughout the day, commentators merely speculated about his intentions – would he do it or was it just a negotiating tactic? – while rolling news channels ran their scrolling text across the bottom of the screen: ‘Tonight, 2am, deadline expires. Will Trump destroy Iran? Follow live on BFM TV.’

The accumulation of crises (ecological, health, economic, energy), the proliferation of conflicts, the genocide perpetrated in Gaza amid the indifference of foreign governments, and the relentless – and ever more frenzied – avalanche of dramatic news stories have acclimatised us to the worst, and brought a sense of powerlessness. So today, any day, could be Iran’s last, but for us, the sun will rise again tomorrow just as it did this morning. So why worry?

This time, Trump didn’t go through with his threat. But in the absence of any resistance, his words did their work. They pushed back the boundaries of what can be said and have already begun to delineate what may yet become possible.