“Metaphors can kill,” the linguist George Lakoff wrote in an influential essay on the Gulf war. “The use of a metaphor with a set of definitions becomes pernicious when it hides realities in a harmful way.” He described the effects of the US employment of business cost-and-benefit analogies, sporting comparisons and the fairytale of the just war with heroes and villains.

All veiled the reality of conflict. Euphemism was long the preferred choice for the US military. Spokespeople discussed “collateral damage” rather than civilian deaths and “surgical strikes”, framing destruction as both precise and part of a necessary and ultimately healing process. Donald Trump chooses naked menace instead. This week he issued a genocidal threat against Iran, having previously threatened to bomb it “back to the stone age” and destroy bridges and power plants – schools and medical facilities having already been pulverised. He said that he was “not at all” concerned about potential war crimes.

When he warned on Tuesday that “a whole civilisation will die tonight” unless Iran agreed a deal, he was seeking an exit from the disastrous war he unleashed six weeks ago. A two-week ceasefire was duly declared, though it appeared at risk of collapse within hours. Talks between Iran and the US, scheduled for Islamabad this weekend, were subject to similar uncertainty. Relief at the halt – above all among Iranians but also felt globally – was shadowed from the first by the risk of renewed conflict. Meanwhile, Israel escalated attacks on Lebanon. It called the 10-minute mass strike that killed dozens of children, a poet, two journalists and hundreds more people, “Operation eternal darkness”.

Euphemism is not entirely dead – the Israeli military has killed hundreds of Palestinians in Gaza since a ceasefire was declared there six months ago. But the deaths of tens of thousands in Gaza, following the Hamas attacks of October 2023, were accompanied by annihilationist statements from Israeli politicians. Mr Trump sought to force the Iranian regime into a deal, but when the commander-in-chief of the world’s most powerful military makes such a statement in the midst of a bombing campaign, on the day of the threatened act, its intent and effect can only to be to terrorise the population too.

The president’s threats would require the military to carry out plainly illegal acts. Though they are legally required to follow only lawful orders, he is increasingly surrounded by sycophants who dare not contradict him, and his administration has systematically weakened the institutional mechanisms constraining the armed forces. Beyond that, as the political philosopher Mathias Risse wrote this week, “the language of civilizational destruction is not merely the symptom of atrocity but one of its instruments”. Regardless of what results, the threat is in itself a war crime.

Experts note that there has rarely been a clearer declaration of intent – and also that holding Mr Trump accountable via international law appears a hopeless endeavour. Yet such efforts, however apparently futile, must be pursued. Israel’s allies allowed it to kill tens of thousands of Palestinians in Gaza with only muted protest, undermining their statements of support for a rules-based order. The pope and a Hollywood actor offered the clearest indictment of Mr Trump’s threat this week. Let it stand without challenge, and the moral, normative and legal standards crumble still further, leaving Iranians and people around the world in peril.

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