The EU Commission announced it could invoke the clause to
impose controls on exports to Northern Ireland -- which unlike mainland Britain, remains part of the Single Market -- to prevent vaccines traveling out of Ireland and into Britain via Northern Ireland. Hours later, Brussels backed down from the threat amid furious protestations from UK and Irish.
But the damage was done.
Brexit's tightly wound terms, dictating an open border between Northern Ireland and Ireland, and controls on Northern Ireland sea border with mainland GB, began unspooling almost immediately. The province's top politician, pro-Brexit First Minister Arlene Foster's retort was predictably icy: "This is an incredibly hostile and aggressive act by the European Union."