When Donald Trump was sworn in as president at the start of last year, many predicted that he would be a less explosive presence in the White House than he had been during the campaign. They hoped that he would be restrained by the permanent political and bureaucratic establishment in Washington and argued that radicals in power turn into compliant conservatives and seek to preserve the status quo.

At about this time, a friend sent me a clipping of a New York Times editorial dated 31 January 1933, with the title “Germany Ventures”. The writer recognised that there were qualms at the appointment as the head of the German government of a man who “has openly scorned it” and threatened to destroy it. But the editorial is reassuringly confident that this would not happen, citing many reasons such as the opposition of his cabinet colleagues who would oppose him “if he sought to translate the wild and whirling words of his campaign speeches into political action”.

Other limitations on the new leader’s power also suggested that nothing much would change: German finances were in strong and conservative hands; attempts to establish a dictatorship would provoke a general strike; German foreign policy would be unchanged; and President Paul von Hindenburg could unmake the new chancellor just as quickly as he had made him.

In a classic piece of political miscalculation, the editorial writer reassured readers: “It may be that we will see the ‘tamed’ Hitler of whom some Germans are hopefully speaking,” he said. “Always we may look for some such transformation when a radical demagogue fights his way into responsible office.” Judgement of the new German leader should be suspended until he had shown if he was more than “a flighty agitator” who would “compel the German people to take a leap into the dark”.

I took the point at the time that the friend who had sent me the clipping was seeking to point out how easy it was to underestimate the degree to which demagogues can be even more power-hungry and destructive in office than they were before. But I did not use the clipping because I felt that it was premature to compare Trump to the elected dictators of the past – of whom Mussolini and Hitler are only the worst examples – who won a majority at the polls and then tried to eliminate all opposition to their authority at home and abroad.

From Napoleon III to Turkish president Recep Tayyip Erdogan today, populist nationalist strongmen have much in common: simpleminded slogans and vague promises guaranteed to win votes, attacks on independent media, contempt for the law (though lauding law and order), control and marginalisation of parliament, chauvinism, militarism, allegations of corruption and an incessant pursuit of power.

President Barack Obama predicted that Trump would find the American ship of state difficult to turn, but turn it did. The “grown-ups” in his cabinet, mostly former generals of whom so much as was expected, have come and gone. Those that remain are ignored and humiliated such as Secretary of State, Jim Mattis, who said that the Iran nuclear deal was doing its job.

Trump has been systematically blowing up the fixed points in American foreign policy, so the political temperature in the Middle East is continually rising. As one commentator put it, there are more unpredictable “moving parts” than ever before in the different crises, parts which may break loose at any moment.

This week saw the US pull out of the Iran nuclear accord and Israel make heavy airstrikes on Iranian targets in Syria. But the coming week may bring almost equally dangerous developments: on 12 May there is the Iraqi parliamentary election in which no party is likely to win a majority. The US and Iran are backing different sides to try to ensure that the next Iraqi government is favourable to them. Iraqis fear their country will be the arena in which the US and Iran fight for supremacy, with the odds favouring the Iranians if only because they, like the majority of Iraqis, are Shia Muslims.

Practical questions will arise after the election: what, for instance, will be the future for the 10,000 US soldiers and military contractors in Iraq but whose presence is not as necessary as it was before the defeat of Isis? As the US imposes stringent economic sanctions on Iran, will it penalise individuals, banks and companies in Iraq doing business with Iran? Iran has every incentive to route part of its business through Baghdad, where the US will have to step lightly in order to avoid alienating local allies.

Within two days of the Iraqi election, the US Embassy in Israel will move from Tel Aviv to Jerusalem. Israeli and American flags will flutter in every street and there will be 150 giant billboards with the face of Donald Trump on them. This will happen on 14 May, the same day as tens of thousands of Palestinians will march in Gaza to try to break through the fence surrounding the enclave.

The demonstration comes at the end of seven weeks of protests called the “Great March of Return” in which the Palestinians sought to reassert their right to return to the land in Israel from which they were expelled or fled in 1947. At least 43 Palestinians have been killed and 1,700 wounded in the protests so far. The peace process between Israel and the Palestinians has long been moribund, but Trump is brazenly saying to the Palestinians that they count for nothing and can expect nothing from diplomacy.

The danger is that, like so many other populist nationalist strongmen, Trump will overplay his hand. From the eastern borders of Afghanistan to the Mediterranean, the US position is not strong. He looks to local powers like Israel and Saudi Arabia but they can do less for him than he imagines. There is a diplomatic price to be paid for ignoring European and other allies who see that appeasement of Trump gets them nowhere and is despised as a sign of weakness.