Nobody is arguing for a return to what is somewhat confusedly referred to as a “hard border”. There is agreement between the EU, the UK and the Republic of Ireland that there
should be what is confusedly called a “soft border”. That is not the problem. The problem is about the constitutional status of a part of the United Kingdom. That is why people are so angry and so worried about the backstop, and why there have already been a good deal of incipient attempts at violence in Northern Ireland, which mercifully did not kill anybody.