All of a sudden, and after years of bluffing, conservatives are warning of the dangers of jumping to hasty conclusions. Before I go any further, I must therefore say our newly scrupulous masters have a point. The league tables of national Covid-19 death figures are not the last word on the crisis, and may look different in a few weeks. That’s that done, then. Everybody happy? Good. Let’s get on with it.

In the world as it is, rather than as it may be, a shameful fact is undeniable. The highest Covid-19 casualties are in the US and the UK, where the mendacities of the populist right have deformed society. It turns out that being governed by Anglo-Saxon conservatives is a threat to the health of nations. Their rule kills the old and blights the futures of the young. To understand their ineptitude, think of how conservatism turned into a know-nothing culture in the past decade, and ask what Donald Trump and Boris Johnson would be doing in an alternative universe where they never came close to power.

I don’t think you need a wild imagination to find the answer. Trump would be propagating corona conspiracy theories about 5G and Bill Gates as enthusiastically as he endorsed the straight lie that Barack Obama was born in Kenya and ineligible to serve as US president. Johnson would have been egging on his colleagues at the Telegraph as they insisted last week the lockdown was a “pant-wetting” response to the virus from a government of “nervous nellies”. When it was Johnson’s turn to offer his two pennies’ worth, he would repeat the Brexit right’s party line that the government had “petrified the public” to the point where it was overwhelmingly against lifting the lockdown and going back to work as it jolly well should. My guess is he would remind readers, for they are never allowed to forget, that he managed a second-class classics degree from Oxford sometime in the 1980s by deadlifting a Latin phrase and announcing “aegrescit medendo” – the cure is worse than the disease. For that is what the world that provided his most loyal support believes.

The British new right, “alt-right”, populist right, call it what you will, sees itself as sceptical and independent, even if its supporters’ reactions to all events are as predictable as speaking clocks. Class plays its part, as it always does in England. We are witnessing the Oxbridge arts graduate’s fear of expertise, particularly the expertise of scientists who cannot cut a good figure or turn a catchy phrase. In Johnson’s days at Oxford, they were dismissed as “northern chemists” – chemist being a catch-all term covering everyone studying subjects the suave could not understand. Northern chemists drank beer, went to comprehensives and were boring as hell. By what right do these nobodies now tell us what we can and cannot do?

For all the unearned superiority of the Brit right, its differences with the US are more of tone than substance. Its American cousins embrace paranoid conspiracism. The Trump administration is now asserting that the virus was developed in a Chinese lab – as if there were not enough valid reasons to condemn what the Chinese Communist party has done. The worst of the British right marches down the same road. It turned Neil Ferguson’s liaison with his lover from a personal failing to abide by his own guidelines into evidence of a leftwing plot. Writing in the Critic, Toby Young, Johnson’s friend and I would say his greatest admirer on Fleet Street, said that, because the lover had campaigned for leftish causes, he was “99% sure” that the majority of scientific advisers everywhere in the world were leftists with an ideology that was pushing governments into panic measures. Confronted with an emergency they do not understand, modern rightwingers reduce complexity to culture war, and dismiss advice they cannot take with the only reason their limited minds can comprehend: the political bias of the “liberal elite”.

It has worked for them until now. Blaming the libs has taken them to power. In theory, today’s crisis ought to suit them, as it has shown the centrality of the nation state. The nationalist right might hope that, along with global supply chains disappearing as countries “reshore” vital industries, multilateral agreements on climate, justice and human rights will vanish. In the world of Trump and Xi Jinping, they did not seem to have much of a chance anyway.

Yet nationalists in power cannot cry “America first” or Britannia Unchained as they turn their nation states into failing states. Most people are not “petrified” because the government has scared them to death but because they see the fatal mess conservatives are making of managing the crisis. I accept that there is a danger on the left of robotically damning everything Tories do, and that if Rishi Sunak had been a Labour rather than a Conservative chancellor, his bold rescue package would have had him cheered at the Durham Miners’ Gala. But come now. The ever-expanding list of fiascos, from failing to lock down early enough, to failing to provide adequate protective equipment. The trickery in pretending that the government was committed to providing 100,000 tests a day when it turned out to be 100,000 tests for just one day. The chaos of an administration that briefs that it will be allowing picnics in parks one minute and denies it the next. Everybody is noticing that the state doesn’t have a grip on the crisis.

As faith melts away, people will be less inclined to believe ministers when they say it is safe to end lockdown, and less inclined to trust the government’s tracking apps. And however much unjustifiable cynicism there is about government, there are good reasons not to trust modern rightwing leaders. As the words of their loudest supporters show, they come from a culture that despises the actions we need to take to protect ourselves. That culture was guaranteed to fail when strong government was needed, and is, as a matter of shameful fact, demonstrably failing today.

• Nick Cohen is an Observer columnist