Give or take the prime minister’s recent 12-day withdrawal from public life, since his party’s victory at the election the government has largely been trading in performance, rhetoric and intrigue. Running through a great deal of what has happened has been the pantomimic presence of Dominic Cummings, showily quoting the animated kids’ series PJ Masks, stoking this or that controversy, and supposedly working on plans for a great national transformation whose practical details may never arrive.

But all of a sudden, things have rather changed. If the ongoing floods have seemed to leave too many people at the top untroubled, the decisive arrival in the UK of the coronavirus has highlighted two things that were in danger of being forgotten: the most basic responsibilities of any government, and the necessity of seriousness.

How might self-isolation work among people in precarious employment who either turn up for work or starve?

As cases increase, anxiety mounts and both the human and economic consequences of the virus’s spread start to become clear, the smirk attached to the face of this government will need to go. Whatever the tangled imperatives of news management, love and fatherhood, the prime minister has to find a better setting than either absence or the mixture of complacency and boilerplate patriotism that he voiced two weeks ago (“We are a great country, we have got a fantastic NHS, we have got fantastic doctors and advice”).

The somewhat cursory parroting of official advice about washing your hands – “with hot water and soap” – that he dispensed last week was hardly any better. Less than a year after the advertising blitz about Brexit that was brazenly and absurdly political, we are now promised a mass public information campaign, which will have to sound a lot more responsible and authoritative than its immediate predecessor.

A good test of the government’s grasp of the situation will be its approach to broadcast media, and what will happen to the Tory view of mainstream news programmes as bastions of remainer mischief. If your first duty is to make sure as many people as possible are fully informed, can you really insist that ministers boycott the Today programme – and, as happened last Friday, leave the former health secretary to tell listeners that the UK is “preparing for a pandemic”? National emergencies tend to necessitate such traditional means of communication, not to mention ministers who are well briefed, prepared to be questioned and unafraid of the public.

What sits under all this is a series of inescapable facts about power. Whatever illusions of control and human mastery are built into governments, unexpected events often reveal something very different: that life is fragile and contingent. The visions of Cummings – and, come to think of it, the revolutionaries who seem to be on their way out of the inner circles of the Labour party – are particularly relevant here: contrary to their dreams of great transformations instigated from the top, to govern is often not to chase grand schemes and bend events to your will, but to simply avoid the worst. Many countries’ current leaders and regimes might affect to be omnipotent, but this increasingly feels like the tenor of our age – something evidenced not just by the coronavirus, but this country’s travails with the weather, the Australian bushfires and more. Even if the latter are the result of human-authored climate change, they have thrown the shortcomings of politicians and the systems of power in which they operate into sharp relief.

In the country where the coronavirus seems to have first passed from animals to humans, the downsides of the Chinese regime’s reliance on denial and obfuscation are now glaringly clear. In the US, it may yet undermine Donald Trump’s hyping-up of the state of the economy, and is already shining light on his administration’s cuts to an array of budgets for branches of government focused on disease and public health. In the UK, the virus’s spread surely threatens the functioning of the NHS – which, we now read, has only 15 beds in England for the most severe cases of respiratory failure. When I read about the central role in local planning to be played by councils, I wonder about a decade of cuts and the disappearance of the kind of institutional memory that is essential in dealing with any emergency. There are questions also to be asked about how an increasingly fragile, fragmented society might deal with something that could entail drastic responses. How might self-isolation work among people in precarious employment who either turn up for work in any circumstance or starve? What of our equally punitive benefits regime?

Last week, as stock markets tumbled and the number of UK cases continued to tick up, I happened to glance at two news stories in short order. One was about Michael Gove reviving the drumbeat of a no-deal Brexit, and insisting that the government would not accept any alignment with EU laws. The other was about Stella Kyriakides, the European commissioner for health, insisting that as the coronavirus spread, “diverging approaches across the EU” had to be avoided, and that the commission should be “ready to co-ordinate among member states should this be necessary”. The juxtaposition of the two triggered a pang of unease.

By way of cheering myself up, I was by then immersed in Pale Rider, the peerless history of the “Spanish” flu pandemic of 1918, written by the scientific journalist Laura Spinney. I consoled myself with the knowledge that what it describes happened before the arrival of widespread vaccines. But there was plenty to project on to now: an illness that had wildly different effects on people and laid waste to some places while leaving others relatively unscathed, and the way the pandemic triggered social and political changes.

“It influenced the course of the first world war and, arguably, contributed to the second,” writes Spinney. “It pushed India closer to independence, South Africa closer to apartheid, and Switzerland to the brink of civil war. It ushered in universal healthcare and alternative medicine, our love of fresh air and our passion for sport, and it was probably responsible, at least in part, for the obsession among 20th century artists with all the myriad ways in which the human body can fail.”

War, illness and disease are often the locomotive of history, dragging things in no end of unexpected directions. Whatever the vanities of politicians, this is a fact for which there is no antidote.

• John Harris is a Guardian columnist