The following words are in italics because they are not my words. They are frightening analysis of a man who should never have found his way to his present job.

Boris Johnson should look Richard Ratcliffe in the eye. If he did, he would catch a reflection of himself that might prove painful but illuminating. For contained in his handling, and fateful mishandling, of the case of Richard’s wife, Nazanin Zaghari-Ratcliffe, is almost every aspect of the Johnson modus operandi. It is a parable of the prime minister’s approach to politics – and to other human beings.

Ratcliffe is in the last stages of a hunger strike that has seen him camped outside the Foreign Office for 20 days and nights, weak, dizzy and shivering from cold. His wife has been detained in Iran since April 2016, and he wants her back home. There are other UK nationals held in Iran, including Anoosheh Ashoori and Morad Tahbaz, but it’s Zaghari-Ratcliffe’s case that implicates Johnson specifically – and says so much about him.

Start with his most infamous involvement, four years ago this month, when as foreign secretary Johnson told a Commons committee that Zaghari-Ratcliffe was “simply teaching people journalism”, apparently oblivious to her insistence that she had been in Iran on holiday. Three days later, Zaghari-Ratcliffe was hauled before an unscheduled court hearing in Iran, where Johnson’s words were cited as proof that she had engaged in “propaganda against the regime”.

In that act alone, you can see the essence of Johnsonism: carelessness, in both senses of the word. Most obvious is the slapdash failure to master his brief, to pay attention to detail. But most egregious is the lack of human care, the cavalier disregard for the impact his actions would have on others. That casualness, that lack of empathy, was a warning to his fellow Tory MPs, one they chose to ignore when they made Johnson their leader less than two years later.

Had they paid attention, they could have anticipated that this would be a man who would turn up at the UN or his own climate conference with nothing more than a few warmed-up jokes and vague exhortations, rather than a willingness to put in the hard, detailed work such diplomacy demands if it is to make a breakthrough. Nor would they have been surprised that he would respond to calls for a Covid lockdown by shouting to his advisers that they should “let the bodies pile high in their thousands”. Careless and without care: the clues were already there.

But the Commons gaffe was not the worst of it. Ratcliffe believes that it was the move that followed a few days later, as Johnson sought to put out the fire he had started, that cost his wife most dearly. Johnson briefed friendly papers that Britain would repay the £400m it owed Iran for an unfulfilled 1970s arms deal, a move he clearly tied to Zaghari-Ratcliffe’s release. According to Ratcliffe, setting that price for Nazanin and not meeting it is “why she is still held to this day”.

Again, that one act contains multitudes. Johnson let people believe he was going to pay off the debt to Iran because he needed to get out of a hole, and that’s how he always is – telling people what they want to hear, issuing promises he won’t keep. In 2018, he assured Unionists that there would be no border down the Irish Sea; a year later he’d made a deal that would put a border down the Irish Sea. He promised “frictionless trade” after Brexit, only eventually to have a colleague admit that there would, after all, be the friction of border checks. Whether it’s £350m on the side of a bus, 40 new hospitals or a continued 0.7% on aid, a nice number thrown out by Boris Johnson should always prompt a swift counting of spoons. Richard Ratcliffe is one of many to have learned that lesson the hard way.

So little in Johnson’s method has changed. Ratcliffe recalls how, straight after the then foreign secretary had made his calamitous remarks four years ago, he “didn’t apologise, but sent his mates out on the airwaves to defend him and to muddy the waters”. That could be a description of last week, when the prime minister dispatched cabinet underlings to embarrass themselves over the Owen Paterson affair. And note how, rather than devising a diplomatic channel or strategy that might reach Tehran and actually get Zaghari-Ratcliffe out, Johnson’s priority was squaring the Daily Telegraph. That remains the default even now, whether it’s the Northern Ireland protocol, the pandemic or the gravest issues of geopolitics: what matters most is keeping the base on side.

All of this would be clear to Johnson if he had wandered out of Downing Street and come face to face with Richard Ratcliffe. But naturally he didn’t do that, even as a simple gesture of compassion. He wouldn’t do it, because that would have meant confronting something awkward and taking responsibility for it. That’s not Johnson’s style, as we saw again this week when he ducked the emergency Commons debate on the Tories’ rising sleaze scandal, sending out one of his human sponges to absorb the mess instead.

He lacks the empathy to look properly chastened by the plight of Zaghari-Ratcliffe. Indeed, he seems unable to feel any shame at all. Any man who has to be told three times to wear a mask in a hospital obviously lacks that capacity. Even so, Johnson is clearly too frightened to face Ratcliffe, a man frail and exhausted with hunger. Perhaps he knows that in the story of that man and his imprisoned wife all his weaknesses are laid bare – and he can’t bear to look.

By Jonathan Freedland, who is a Guardian columnist