Ese problema se debe a un compromiso conjunto entre el RU y la República de Irlanda de mantener una frontera “sin fricciones” entre el segundo país (que permanecerá en la UE) e Irlanda del Norte (que como parte del RU, se irá con él).
That problem arises from a commitment by both Britain and the Republic of Ireland to keep a “frictionless” border between the Republic of Ireland, which remains in the EU, and Northern Ireland, which, as part of the UK, leaves it.