A thought experiment.  Let’s imagine as total a shutdown of Britain as it is possible to manage.  Schools closed, offices empty, shops shut – save those selling food.  Minimal public transport.  Airports closed. Older people deliberately isolated.  No public events.  An economic freeze.  The country sealed off.

Sooner or later, the freeze would have to thaw: the Government would signal a return to as near normality as possible, and people would begin to emerge blinking, like post-hiberation bears, from their homes.

At this point, Boris Johnson and his advisers argue, they would run slap bang into the waiting Coronvirus.  There would be health service carnage.  The NHS would be unable to cope, in the manner of Italy’s hospitals now.  The death rate would climb to – what? – six per cent; seven per cent; more.

In this view of events, the Coronavirus is like an invading army.  If you hunker down, wait for it to pass, and then emerge dazzled into the spring sunshine, it will then ambush you, cut you down and defeat you.

The Prime Minister’s plan is, rather, for a national fight back.  This will come not so much through the eventual deployment of a vaccine, like some battlefield nuclear weapon, but through acting as close to Carry on Britain as it is possible to do.

In that way, the population will acquire “herd immunity”.  This will beat the virus in the medium term, and flatten its peak in the short – staggering out those hospital admissions over time, and thus preventing the NHS from being over-run completely.  This is the core of the case argued this week by Patrick Vallance.

That it is made by the Government’s Chief Scientific Officer doesn’t mean that it represents “the science”.  For strictly speaking, there is no such thing.

Rather, Johnson is being guided by a plan partly based on a certain scientific reading of events.  Some scientists agree with it; others don’t.  That’s in the nature of the beast.  Probably because, as ConservativeHome keeps repeating, the decisions that the Government must make are not scientific, but political.

We thus find ourselves in the odd position of agreeing on paper with Rory Stewart, who has made precisely this point, while not agreeing with his call for a China-type response in practice.

He is correct to suggest that the Government’s actions can’t turn on “the science” because ultimately they must hazard a guess on the behaviour of human beings – which is not a science; or at most is a social one.  And it may be that the Prime Minister’s strategy, so unlike that of most other comparable governments, is fundamentally flawed.

This would be because people will behave in a more disciplined way that the Government’s modelling suggests; or because “herd immunity” can’t be acquired so quickly, or because draconian responses are the example to follow.

To follow our wartime analogy, this interpretation of what’s happening sees Johnson as an Oh What a Lovely War general of legend, needlessly sending a generation of older people “over the top” to die amidst the virus’s equivalent of barbed wire and poison gas.

None the less, we think there is a solid case for the Prime Minister’s approaching – carried out against the prevailing practice elsewhere, lauded as successful, by Jeremy Hunt, in a series of Far Eastern countries and places.

This isn’t to say that the Government is getting everything right.  The advice from 111 to people returning from Italy lagged behind changes announced by Public Health England.  Johnson was slow to concede that the local elections should called off.  111 has sometimes given conflicting advice.

But there are three solid points to make in Johnson’s favour.  The first is that the very same people who were only recently denouncing him as a Trumpite populist monster are now excoriating him for being not populist enough.

Charlotte Gill made this case on ConservativeHome yesterday.  And if the debate was, frankly, Vallance v :Piers Morgan, one wouldn’t hesitate for a moment about whose side to be on.  But it is not quite as simple as that: for as we point out above, some scientists disagree with the Chief Scientific Adviser.

The second point is a development of the first.  Governments like to tell voters that all will be well – in the case of this one, that it will succeed in “levelling up”.

But perhaps the levelling that matters most is levelling with the British people.  If a Prime Minister is willing to tell them that “many more will lose loved ones before their time,” this sounds like a candid, politically risky statement of truth from a man accused by his enemies of telling nothing but lies.  It commands respect.

War analogies in politics are dangerous, but there is something in the one that this site uses today.  The struggle against the Coronavirus will be a real war with real casualties.  Our snowflaky, social media-focused, Me Too culture may cope, but it is unprepared for it, and there has been nothing like it in most people’s living experience.

In these circumstances, Britain’s institutions may be a strength.  We don’t just mean right-of-centreish ones – like our first past the post system that has delivered a Government with a near landslide majority of 80.

We mean a centralised, nationalised healthcare system – itself a product of wartime thinking; not always suited to peacetime, but well set up for a command-and-control-led crisis.  Or a state broadcaster that can carry public information which commercial rivals are under no compulsion to carry.

This brings us to a third point in Johnson’s favour.  The European Union’s response to the virus has been torpid; Trump’s schlerotic; China is grappling with its debt burden.

A combination of a Corovirus-driven downturn, oil price wars, corporate debt and the lack of leadership from the EU institutions and the American President threaten a real crisis for the world economy.  Amidst these seething, turbulent waters, the Prime Minister’s majority looks like a rock.

Gordon Brown was mocked during the financial crisis for mis-declaring at Prime Minister’s Questions that he had “saved the world”.  But now that we look back at it, the old boy didn’t do badly in the hour of need – despite his responsibility for some of Britain’s biggest pre-crisis mistakes.

Johnson is no Brown in almost any sense.  He is mistrusted by the EU and apparently alienated from Trump, at least to some degree, by his decision to keep going with Huawei.

But together with Emmanuel Macron, he is a strong domestic leader.  As Ambrose Evans Pritchard argues in the Daily Telegraph, the two might just have the capacity, acting together as Britain and France still do on defence, to drive a global plan to tackle the virus.

Working together on an international fiscal and monetary stimulus package could conceivably make a difference.  Something on that scale is needed.  After all, this is a global and not merely a national conflict.

Whatever happens, we close with a hard thought.  Perhaps here at home, Johnson will succeed in “flattening the peak”.  However, we promise our readers that it won’t feel like success.  The NHS will still be over-run.  A & E departments will turn the sick away.  There will be agonising horrors.  The service risks tottering to its knees.