Pity the people of America. They do battle now with one of the greatest challenges in their history, led by a man who is not only among the worst ever occupants of the White House but whose character makes him the last person on the face of the Earth you would nominate to be in charge at this moment. On Thursday the US reached the top of the global league table for coronavirus infections, edging ahead of its closest rival for that honour, China. No law of nature dictated that outcome. Much of it is directly attributable to one dreadful fact: that Donald Trump is president of the United States.

It’s become a commonplace to note Trump’s lack of basic human empathy, his tendency to be unmoved by others’ loss. But that gap in his mindset matters now far beyond an inability to offer consolation to the bereaved: it is warping his approach to a lethal disease.

“WE CANNOT LET THE CURE BE WORSE THAN THE PROBLEM ITSELF,” he tweeted in caps lock at the start of the week, shortly after Steve Hilton, one-time adviser to David Cameron, had made that same argument on his Fox News show. (If you look up the word “chutzpah” in the dictionary, it now directs you to a clip of Hilton warning on that same broadcast that austerity policies in the UK caused an extra 130,000 deaths – failing to mention that he was at the right hand of the prime minister who imposed that austerity.)

Trump and his outriders contend that, while mass death is not ideal, it’s better than allowing the US economy to stall. Some, like Texas lieutenant governor Dan Patrick, are explicit, urging the elderly to risk their lives so that their grandchildren might enjoy the fruits of uninterrupted American capitalism. “If that’s the exchange, I’m all in,” Patrick said. He was taking his cue from Trump who, while not putting it quite as baldly, has been quite clear. If coronavirus is a stick-up artist asking America, “Your money or your life”, Trump’s response has been: “Take the lives of the old and the weak: I want the money.”

An imbecile at the head of the US government would always be a problem. But this is a calamity

Of course, no such choice is available. Even if Trump were to get his way, ditching social distancing and having the US open for business by Easter, the disease would not politely confine its appetite to the groups Trump has deemed dispensable. Instead the virus would run rampant, infecting an estimated half the population. Not that Trump would know or recognise that, thanks to a second character trait that, like the void where his sense of compassion should be, is so fatefully, and fatally, determining the US response to this pandemic: namely, his disregard for science.

“This is just my hunch,” he said as he dismissed a projection of the likely Covid-19 death rate by the World Health Organization as “a false number”. On Thursday, he said “I have a feeling” that New York would need far fewer ventilators than the tens of thousands the state has requested. “You know, you go into major hospitals sometimes, they’ll have two ventilators. And now all of a sudden they’re saying can we order 30,000 ventilators?” An imbecile at the head of the US government would always be a problem. But an imbecile so narcissistic that he elevates his own stunted knowledge above the judgment of medicine and science is a calamity.

The effect is to undermine whatever public health effort the professionals can mount, as they try to work around the man they serve. At its most visual, it’s the daily press briefing where Trump fails to observe the social distancing measures his administration is demanding of the American public, with himself standing at the centre of a cluster of speakers bunched together by the podium. Note the initial insistence that corona was nothing to worry about, that it was no more than flu, that it would soon disappear, like a “miracle”. All of that succeeded in lowering Americans’ guard.

Since then, it’s been the daily grouching at the stay-at-home directives, the hint that they’ll be relaxed soon, the absurd promises that a vaccine is “very close”. The impact is plain to see, in data that confirms that Americans break down on partisan lines even over the most basic matters of mortality. One in four Republicans still say they are “not concerned at all” about the virus – while only 5% of Democrats are similarly unbothered. Only 14% of Democrats trust Trump for information on the virus, compared with 90% of Republicans. Put simply, there is a body of Americans who do not take this threat as seriously as they should, and the blame for that lies with the president.

Trump’s dishonesty matters here too. He was rightly derided in 2016 as a “snake-oil salesman”, and the cliche is so well-worn it’s easy to forget what it originally refers to: the 19th-century hawkers who sold bogus cures to the gullible. Recall that Trump rushed to tell people a pre-existing drug would cure Covid-19, leading to a shortage of a medication that was needed for other illnesses, and several deaths, as desperate people rushed to buy tablets that, for them, proved lethal.

The US president always was capricious and vengeful, but now that character flaw is a matter of life and death. State governors are crying out for federal help, not for themselves but for the people they represent: the nurses and doctors who need protective equipment and testing kits, the patients who need ventilators. But instead of leaping to their aid, Trump tells the governors it’s their responsibility, even though they have a fraction of the procurement power of the US government – adding that if they want help, they’d better grovel. “It’s a two-way street,” Trump said this week. “They have to treat us well.” Even when lives are on the line, his ego with its paper-thin skin comes first.

Americans are paying the price for his lack of foresight, his closure of a pandemic task force for no better reason than it was established by Barack Obama – he hates anything with his predecessor’s name on it – and his failure to heed the warnings of a pandemic preparedness exercise, codenamed Crimson Contagion, that identified glaring gaps as recently as last October. Yet still he repeats the line that nobody could have known what was coming. And they are paying the price for his weakness, as he demands steadfastness in a war against an “invisible enemy”, only to leave heavy hints that he’s ready to fold after a week, apparently deciding that 15 days is too long to stay at home.

America is lucky it has a federal system that means not all power lies with the president, that at least some rests in the hands of responsible mayors and governors, the likes of New York’s Andrew Cuomo. The nation is lucky too that the House of Representatives is controlled by Democrats, who crafted a $2.2tn economic bill from what would otherwise have been a trough into which Trump’s corporate pals could sink their snouts.

But these are small consolations for America and indeed for the world, which needed the leadership only a US president has the clout to provide. Instead, the world’s peoples now look at the US and comfort themselves with the small solace that they, at least, face only a lethal disease, and not the malignancy that is Donald Trump.

• Jonathan Freedland is a Guardian columnist