David McKittrick: Hero of Ulster peace process sent to Middle East

George Mitchell is remembered in Ireland as one of the heroes of the peace process, a superlative political operator who played a crucial role in helping to the end the violence.

In his years of involvement in Belfast, the former senator helped steer the process through violent incidents, political crises and countless times when it appeared fated to be stalled in stalemate. He is now recognised by most participants for his skills in keeping the process alive when it seemed to have failed and for his refusal to be daunted by the huge task of bringing ancient enemies together when that goal often seemed hopeless.

He was sent across the Atlantic during the 1990s by Bill Clinton, who took a personal interest in the Troubles. On arrival in Belfast, he was first engaged in the highly difficult issue of weapons decommissioning, eventually proposing a compromise by which armed groups would retain guns while the negotiations went on.

Later, he became the chairman of the talks which finally brought Ulster Unionists and Sinn Fein into the same room and which led to the breakthrough Good Friday Agreement in 1998.

His grandparents, who were called Kilroy, had emigrated to America from Ireland. His father was adopted by a janitor and his Lebanese immigrant wife but, from this unpromising start, he became a prominent figure in American public life.

He was by turns an army intelligence officer, a trial attorney and a federal judge. A liberal Democrat, he spent 14 years as a US senator. He was the majority leader in the Senate, where, for six consecutive years, his peers voted him the most respected member. After retiring from the Senate he turned down a nomination to the Supreme Court.

In Belfast, one of his characteristics was inexhaustible patience. Another was his view that a process should go on, no matter how hopeless things looked. He said: "At the heart of all the problems in Northern Ireland is mistrust. Each disbelieves the other. Each assumes the worst about the other."

Mr Mitchell helped build an agreement which did not depend on trust but which was festooned with safeguards and guarantees. He has maintained an interest in Belfast politics and has established the George J Mitchell scholarship that enables Americans to study at universities across the whole of Ireland.

In his memoirs, he outlined a philosophy which he will be carrying with him to the Middle East: "I've been involved in Northern Ireland long enough to know that every step forward is followed by a step backward. That it's good not to get too high at the good moments, nor to get too low at the bad moments.

"That you build on this process, you do what you can under the circumstances that exist at the time, and then you proceed from there. But this has been centuries in the making; it will be years in the changing."