The September 11th terrorist attacks ultimately pushed the IRA to decommission its weapons, an Oireachtas special event has heard.
A panel of key players in the Good Friday Agreement (GFA) gathered to mark the 25th anniversary of its signing.
David Kerr was the Ulster Unionist Party's (UUP) Director of Communications at that time.
Decommissioning was "absolutely seismic" for the IRA, he said, "and that's what took them so long to do it".
It only came about when "everything changed" after 9/11, "because Irish America said to the IRA at that point, 'Guys, look terrorism isn't a good look here anymore'".
"The first act of decomissioning followed not long after," he noted.
Asked by moderator, Sean O'Rourke, if she agreed, Bríd Rogers, a former SDLP minister, replied, "I do share that".
She said that "it was somewhat ironic" that it was Senator Ted Kennedy who told the IRA, "You got to know when to hold them, and know when to fold them."
"They were going to lose sympathy in Irish America", Ms Rogers said, as they "suddenly realised what terrorism was, because they'd been hit themselves".
During the negotiations, Derek Henderson was Ireland Editor of the Press Association.
He admitted publically for the first time that during the implementation phase of the agreement he did something that he "had never done before".
"Around November 1999", he recalled being in a Sinn Féin briefing where "they were making it clear" that "there won't be any decomissioning".
Mr Henderson "pulled [the] story" to give some space to David Trimble, the then-leader of the UUP and a key architect of the GFA, who was under massive pressure on the issue.
He also revealed that "when the agreement was signed off, I called my staff together in Belfast and said, 'Listen, this is a pro-agreement office. Anyone who opposes it will be either the last paragraph or the penultimate paragraph in the story."
"He wasn't the easiest of people", he said of David Trimble. "He was edgy. He was awkward. He was uncomfortable."
But he insisted that history will judge Mr Trimble kindly, and deservedly so.
David Trimble and John Hume jointly won the Nobel Peace Prize.
At one point during the event, amid strong questioning from Mr O'Rourke, former Sinn Féin leader Gerry Adams recalled the many previous clashes between the two men.
"We refought the war - now we're refighting the Peace Process," he said.
