LONDON (AP) -- Former U.S. President Bill Clinton and ex-British Prime Minister Tony Blair were heading to Belfast Tuesday to mark the 20th anniversary of Northern Ireland's peace accord, as Brexit casts a shadow over the deal's future.
Clinton and Blair are due to attend an event at Queen's University Belfast with other architects of the Good Friday Agreement, including former U.S. Sen. George Mitchell and Ireland's former prime minister, Bertie Ahern.
The deal, signed on April 10, 1998, largely ended three decades of sectarian violence in which more than 3,000 people died. Over the following years the Irish Republican Army and other paramilitary groups renounced violence and destroyed their stockpiles of weapons, and the British military dismantled its bases and checkpoints in Northern Ireland.
But two decades on, one of the peace deal's main achievements — a Protestant-Catholic power-sharing government for Northern Ireland — is in limbo. The administration collapsed in January 2017 and attempts to restore it have faltered over the issue of protections for the Irish language — a sign of the cultural and political issues that still separate Northern Ireland's British unionists and Irish nationalists.
Britain's impending departure from the European Union threatens another product of the peace process, the all-but invisible border between Northern Ireland and the Republic of Ireland.
After Brexit next year, it will be the only land frontier between the United Kingdom and the EU. Both sides say there should be no return to customs posts or other border infrastructure, but it is unclear how that will be achieved.
Blair says he believes the peace deal "can and it should survive Brexit, but you can't deny that there is now a problem."
He said that over the last 20 years the border had become "of no great practical meaning to people in the north or the south ... Now there is going to be a practical border so of course it's a complication."
"Peace has to be worked on continuously. It is not guaranteed," Blair told reporters on Monday. "Brexit is complicating things, but the Good Friday Agreement has to survive Brexit."