Not only does he have to square the circle of how to have a hard border between the UK and the EU but not between the Republic and the North, he also has to contend with the Gordian knot of politics in Northern Ireland, a place where even asking for directions – which way to Derry or Londonderry? – can mark you out as being in one camp or another, with everything you say thereafter interpreted in this light.
According to DUP leader Arlene Foster, Barnier has been spending too much time with the other side.
He was “not an honest broker” and “does not understand the wider unionist culture of Northern Ireland”, she complained.
Perhaps she thinks the French politician needs a crash course in history. She may wish to miss out the day in 1988 when her party’s founder, the Rev Ian Paisley, displayed the extent of his cultural understanding by shouting “I renounce you as the Antichrist” during a 1988 speech to the European Parliament by Pope John Paul II about shared Christian values.