Screen Shot 2017-01-29 at 08.19.06A British citizen who was naturalised can be identified as such from his passport.  It is on that basis that immigration lawyers have advised Nadhim Zahawi, who was born in Iraq, that Donald Trump’s effective ban on Muslims from seven countries entering America applies to him.  ConservativeHome spoke to our columnist our earlier this morning, and he said that the most important point about the bar is not the distress caused to him and his wife, but that it will blight the struggle against ISIS and Islamist extremism (however much it may please parts of the President’s core vote).

It will be countered that the ban is unconstitutional, is already being struck down by judges – and, furthermore, is only a temporary measure, put in place for three months or so until a new and more strenuous vetting procedure can be put in place.  Nor, it will be argued, does it specifically bar Muslims.  For these reasons (the argument runs on), it is all a typical Trump-style storm in a tea cup, and is in any event none of our business.

This view does not hold.  That the ban is surely unconstitutional, and is already being obviated by judges, has not stopped the President trying to implement it.  And that it is a holding device does not stop it harming the very cause – the fight against ISIS – that it claims to help.  It feeds rather than drains the swamp in which support for Islamist extremism festers.  (And you are far more likely to be shot by another American than by a foreign jihadi.)

It also damages those who are helping to do the draining.  No One Left Behind, a charity that seeks to bring to the United States Afghanis and Iraqis who worked with the American military, says that the ban has caused their programme to be suspended.  These include people who have been placed on death lists by the Taliban and ISIS the work they did with the US military.  We had the same issue with Afghan interpreters.

Nor can the claim that the bar is nothing to with us be sustained.  Zahawi aside, there are some 250,000 people who have dual British nationality and were born in Iraq, Iran or Somalia.  Trump has put his guest of last week in an impossible position.  On the one hand, Theresa May needs him for that trade deal and for help with Brexit.  On the other, she cannot stick to a say nothing script when British citizens can be affected by what he does.  Her attempt to do so yesterday lasted only a few hours.  The visit of the President to Britain later this year, and his proposed meeting with the Queen, is shaping up to be the mother of all diplomatic headaches.