Nothing is more sensitive in Iran than the prospect of direct negotiations with the United States, particularly when the president in question is called Donald Trump.

This is the same Donald Trump who, in 2018, wrecked the first nuclear deal by imposing “maximum pressure” on Iran even though the regime had, contrary to habit, been keeping the agreement. Then Mr Trump authorised the killing of Qassem Soleimani, a brutal Iranian general who the Ayatollahs were busily promoting as a national hero.

So you can be sure that Iran’s leaders did not want Mr Trump to tell the world that direct talks will begin on Saturday, let alone to make that revelation alongside their arch enemy, Benjamin Netanyahu, the Israeli prime minister.

Thanks to Mr Trump’s customary contempt for discretion, America’s new effort to settle the confrontation over Iran’s nuclear ambitions has got off to the worst possible start.