HERE is something that you may not have noticed amid all the to-and-fro of President Trump’s protracted peace negotiations with Iran. Back in the United States, the President has announced that he intends to sue his own government over a leak of his tax returns during his first presidency.

With his customary judicial hyperbole, Mr Trump demanded $10 billion by way of compensation. “I’m supposed to work out a settlement with myself,” he told one reporter. He then announced that he would withdraw his legal action if the federal government instead set up a $1.8-billion fund to compensate individuals, such as him, who had been the victims of “lawfare” — in which the Biden administration used the law to persecute him and his cronies.

Last week, the US Treasury was directed to set up a fund — financed by taxpayers, and controlled by Mr Trump and his appointees — in what is possibly the most brazenly self-serving action by a President whose administration has been characterised by a shameless and unprincipled “flat out corruption of the judicial system”, one US Senator said. “America has never seen corruption on this scale take place inside the White House,” another Congressman said.

A few days after the announcement, I went to see the RSC’s new production of Bertolt Brecht’s The Resistible Rise of Arturo Ui, a dark satire on Adolf Hitler, portrayed as a small-time gangster who seizes power in Chicago by taking control of the cauliflower monopoly in the city’s vegetable market by ruthlessly disposing of the competition. Written in 1941 as an allegory for the rise of fascism, it was intended as a warning about how democratic societies become complicit in their own corrosion. It feels unnervingly timely.

In a classic protection racket, Ui tells local businesses that he will provide safety from violent threats, which are, of course, created in the first place by the gangster’s own hit men. The racketeer presents himself as society’s strongman defender against disorder. President Trump similarly warns his followers of the dangers of fictitious electoral fraud, hostile judges, treacherous media, liberal elites, the “deep state”, and hordes of immigrants. The brutalities of Mr Trump’s immigration stormtroopers are uncannily echoed on stage by Ui’s hooded thugs. Fear, Brecht understood, can become a mode of governance.

We see Ui — played as a chilling comic grotesque by Mark Gatiss in Hitlerian moustache and preposterously uncontrolled fringe — learning oratory, posture, and movement, as he grasps that power comes from performance in a way familiar now from the Trumpian spectacle of the public rally, choreographed grievance, and ritual humiliation. Ui corrupts institutions, newspapers, businessmen, and judges much as Mr Trump has undermined election officials, law firms, universities, intelligence agencies, and other institutions designed to constrain presidential power.

Yet, Brecht’s sharpest insight is not simply about the demagogue: it is about the elites who enable him. Conservatives excuse him as useful. Business leaders delude themselves that they can use or control him. Citizens come to accept as inevitable what would once have been intolerable. The abnormal becomes ordinary.

Democratic decay is not inevitable. It happens when societies accommodate what once they would have rejected. Brecht told us 80 years ago that the rise of Arturo Ui was resistible. It is a warning that the world has failed to heed.