New Delhi, June 23 -- Brexit fractured the European Union, and broke British politics.

The U.K. is about to get its seventh prime minister since June 23, 2016, a decade ago Tuesday, when the country voted 52%-48% to leave the EU after more than four decades of membership. Conservative Prime Minister David Cameron, who called the referendum but campaigned for the U.K. to stay in the bloc, quit the next day.

His successors have all grappled, largely unsuccessfully, with the consequences of that rupture. The latest is Labour Prime Minister Keir Starmer, who announced Monday that he was stepping down after two years of a sluggish economy, malfunctioning government and a divided and jaded electorate - all legacies, at least in part, of Brexi...