Afghanistan flag

It can doubtless be argued that the 1951 Refugee Convention, which defines a refugee as having “a well-defined fear of being persecuted, will soon apply to almost the entire female population of Afghanistan.

That’s some 18 million people, if one roughly halves the country’s population, before one moves onto men – a huge slice of whom will presumably be covered by the “political opinion” element of the definition.

This isn’t to say for a moment that most Afghans, let alone millions of them, will shortly be en route to Dover.  But Boris Johnson will need to consider his fledgling policy for Afghan refugees, currently being drafted, in the context of the asylum landscape as a whole.

The terrifying pictures of people falling from departing planes, a sense of our soldiers’ lives lost for nothing, humiliation as we confront the limits of British power – all these are swelling the clamour that Something Must Be Done.

In the absence of doubling down on military intervention (which is impracticable without the Americans and wouldn’t have public support in any event), the Something To Be Done is to take in a significant number of Afghan refugees.

How many?  The model for the Prime Minister’s scheme will presumably be modelled on David Cameron’s scheme for Syrian refugees: some 20,000 people have been admitted to Britain under it.

The Government is unlikely to allow fewer, both because the likely fate of Afghanistan compels it (the high politics of the case) and because Ministers won’t want to appear more stony-hearted than their Coalition predecessors (its low politics).

How many more Afghans are admitted will hinge, at least partly, on the Government’s collective sense of obligation.  Start with the obvious: embassy staff, military contractors, interpreters, Chevening scholars (after campaigning by David Lidington and Rory Stewart).

Next, women judges, say, or democratic politicians.  Some would widen the door further, admitting those who have set up girls’ schools.  They argue that Britain has a moral obligation to those Afghans who worked with our armed forces, diplomats, aid workers and media.

It’s easier to say Amen to that principle – as we do – than to make it work in practice.  There will be problems of proof (the wider the door is opened, the bigger these will grow), practice and definition.

On which note, have a look at Fiyaz Mughal’s recent piece on this site about the Afghan translator for our armed forces who wasn’t covered by the Afghan Locally Employed Ex-Gratia Scheme.

Complementary to admitting refugees here is helping them on Afghanistan’s borders.  That means aid to its neighbours, who are likely to be destablised, during the coming months and years, by the flight from the Taliban.

Britain has a political as well as a humanitarian imperative to act.  Do you distrust Imran Khan’s government in Pakistan?  If so, you might dislike its replacement, were it unable to cope with the influx, even more.

Do you fear the consequences of hundreds of thousands of Afghans heading for Europe?  If so, you will prefer them to be fed, housed, treated and occupied near their own country.

That possibility raises three cautionary points about Afghanistan and ayslum.  First, there’s an overlap between those who want large numbers of refugees admitted and those who enthusiastically support military intervention.

To be sure, the anti-war left is pro-migration of almost any kind, but it follows that there is also an overlap between those with a more isolationist view of the world and those who are reflexively opposed to immigration.

We’re not hearing much at the moment from that section of the electorate, and there is unlikely to be organised opposition to a Syria-style refugee scheme.  But this takes us, second, to the potential interplay between Afghan refugees and small boats.

ConservativeHome believes that there will be less public sympathy for Afghans who arrive in Britain via illegal routes than legal ones (though it goes almost without saying that most of those who flee Afghanistan will stop somewhere else rather than move on here).

Nonetheless, some will come, and Britain is no longer a member of the EU’s Dublin system.  It doesn’t want to be, but replacement deals are sketchy.  And broadly speaking, the Government’s plan to toughen up the asylum rules will meet a thousand legal challenges.

More narrowly. our courts are certain to take the view that Afghanistan is, as a rule, not a safe country to which those who appeal can be returned.  At which point, a third consideration comes into play.

What about those who claim to be Afghans but aren’t?  Or who take advantage of any lasting decision to waive passport requirements?  (Nigel Farage is already on the case.)

In the short-term, all we will hear, including in Parliament tomorrow, is calls for a generous asylum scheme.  So it will and should be.  But as the Taliban tightens its grip on Afghanistan, media coverage of its agony will relax.

And in the medium-term, after the legal entries enter under the Government’s scheme, illegal ones will come via the boats.  At which point, public opinion will reverse ferret – if you believe, that is, that the present feeling for the terrified Afghans runs wide or deep or both.