Stones in the road

Sir, – When Diarmaid Ferriter refers to Brexit as "another milestone that complicated Anglo-Irish and North-South relations" ("The challenge presented by British disinterest in the North is as big as ever", Opinion & Analysis, February 19th), I wonder whether he was mixing his metaphors or whether he was the subject of a misprint .

In the days before sat-navs, milestones were useful aids to understanding how much further you had to go. There was no complexity involved. Brexit as a millstone would have been a more appropriate analogy. – Yours, etc,

KEVIN O’SULLIVAN,

Letterkenny, Co Donegal.