Britain risks isolation as the president-elect prioritises relations with the EU. The government must understand the signs of the new times

The Irish question has played havoc with the best-laid plans of hardline Brexiters. Since 2016, successive Conservative governments have struggled to square the circle of keeping the United Kingdom intact, while avoiding the reimposition of a hard border on the island of Ireland. The border issue has been the achilles heel of Brexit, the thorn in the side of true believers in a “clean break” with the EU. So the prospect of an Irish-American politician on his way to the White House, just as Boris Johnson attempts to finagle his way round the problem, is an 11th-hour plot twist to savour.

Joe Biden’s views on Brexit are well known. The president-elect judges it to be a damaging act of self-isolation; strategically unwise for Britain and unhelpful to American interests in Europe. But it is the impact of the UK’s departure from the EU on Ireland that concerns Mr Biden most. This autumn, he was forthright on the subject of the government’s controversial internal market bill, which was again debated on Monday in the House of Lords. The proposed legislation effectively reneges on a legally binding protocol signed with the EU, which would impose customs checks on goods travelling between Britain and Northern Ireland. In doing so, it summons up the spectre of a hard border on the island of Ireland, undermining the Good Friday agreement. Mr Biden is adamant that the GFA must not “become a casualty of Brexit”. He is expected to convey that message, in forceful terms, when his first telephone conversation with Mr Johnson eventually takes place.