How did we get into this Brexit mess? Why is it proving so difficult to leave the EU? Was it Theresa May’s botched 2017 election, which vaporised her Commons majority? Or perhaps her general incompetence and lack of vision?

How about the fierce determination of Europhile civil servants to save stupid Leave voters from themselves, cooking up a half-in-half-out withdrawal guaranteed to split the Tories?

Maybe it was the cynical ambivalence of HM’s Opposition, with Labour simultaneously backing both Brexit and a second referendum, having always intended to cause chaos and spark a general election by voting down the UK’s exit, contradicting...