In Cardiff on a Monday that may one day be remembered as a turning point, the nationalist leaders of Scotland, Wales, and Northern Ireland signed a joint declaration signaling their shared conviction that the United Kingdom's constitutional order is nearing its end. Emboldened by an American president's casual endorsement of Irish reunification, three parties that have long pursued separate paths now speak with a single, coordinated voice. It is a moment that transforms what was once a collection of aspirations into something closer to a formal negotiating posture — and places Westminster in t