Britain has finally declared war on Covid-19. Ministers say that the science left them no alternative but to fight. This was never a war of choice. The virus is no ordinary foe. It knows no borders. Having found a human host somewhere in the Chinese city of Wuhan a few months ago, the virus has caused more than 190,000 diagnosed cases of Covid-19, from South America to New Zealand. It was clear that if Britain could not slow down the contagion, the disease would overload hospitals and kill hundreds in a few weeks, as it has done in northern Italy. That Boris Johnson did not fathom the depth of the danger is worrying. The policy to combat a virus must be guided by science, but it is ultimately a political decision. What was obvious in Lombardy only became clear to Downing Street in the form of an analysis by epidemiologists at Imperial College London. Advertisement Mr Johnson must now recover the trust he lost because the public perceived a greater risk to their health than he seemed to assess. There is a long and difficult road ahead. The Imperial model suggests that, unless a vaccine is found before, Britain will come in and out of a shutdown for two years – where schools and universities are closed, social distancing of the entire population is enforced, and households and individuals with signs of the virus self-isolate. These measures would be triggered if hospitals record 200 intensive care unit cases per week, to ensure the NHS can cope with the burden. They would only be relaxed when the influx of patients to the NHS falls away. We are living in a different world, one in which it looks as though quarantine discipline will be required for long stretches of time. In a democracy the lockdown will have to be largely self-policed and not heavily infringe on people’s rights. People have proved themselves to be extraordinarily resilient. But individual fortitude, human kindness and local solidarity cannot replace the radical national effort required. Ultimately, it is only the state that can ensure the scale of action necessary to show that life can continue with security, and to equalise sacrifice across the population. Mr Johnson said he will do “whatever it takes” to protect jobs and incomes. There is an urgent need for targeted measures to support business cashflows so firms can pay wages and avoid layoffs, to back gig economy workers, and to suspend mortgages, rents and household bills. At least £330bn – 15% of GDP – in cheap business loans would be available. It is unclear what assistance key sections of society such as renters will get. More radical measures are needed to help struggling firms keep workers. And there’s a lack of clarity over extra cash for those on sick pay. The head of Britain’s fiscal watchdog said the economy faces a “wartime situation” and not to be “squeamish about one-off additions to public-sector debt”. The analogy only works so far. Wartime maximises production. Lockdowns minimise production. The solution is not to dwell on GDP. That will inevitably fall in a shutdown, which requires us to transact less intensely. Instead, we need to focus on social wellbeing and health outcomes. Isolation might see us spend too long on social media, a super-spreader of fear. It is time to consider a job guarantee programme, with work provided by the state. Welfare will need to be more generous, with broadened eligibility, and public services rebuilt. There is an opportunity in this crisis – which Mr Johnson should seize – to redefine what governments can do. As Lord Keynes said of the second world war: “We threw good housekeeping to the winds. But we saved ourselves and helped save the world.”