This past July 15 was an unusually clear day in London. Thousands of tourists stood quietly outside the gates of Buckingham Palace watching the changing of the guard, whose marching steps echoed across the courtyard. The scene etched itself into my memory as my family and I turned to enter the palace. I was about to be knighted by Queen Elizabeth II.

Although use of the title is reserved for British citizens, the gesture was nonetheless generous, bestowed by a government grateful for the role I had played in chairing the negotiations that led to the Good Friday agreement of April 1998. The British and Irish governments and eight political parties had struggled for two years to reach the historic accord and end decades of conflict in Northern Ireland. I had led the negotiations at the request of the governments, and when I returned to the United States that spring, exhausted but elated, I was convinced that my work in Northern Ireland was finished. I was wrong.

Being knighted by the queen was memorable. But even more memorable were the events taking place simultaneously in Northern Ireland. By an awful coincidence, the peace process was collapsing in a welter of recrimination and anger over implementing the agreement. At a news conference following the palace ceremony, the questions were awkward.

How did I feel about being honored for an agreement that was failing? Very bad.

Was I embarrassed? Yes.

I asked other questions of myself: Had my efforts been wasted? No. Despite this setback I knew there had been a lot of progress.

Would Ulster slide back into sectarian warfare? I hoped not, although no one could be certain.

That evening, instead of celebrating, my wife, Heather, and I sadly watched the television news. The telephone rang, piercing our gloomy silence. It was Mo Mowlam, the British secretary of state for Northern Ireland, asking me to return to Belfast to conduct a review of the peace process. Within minutes, Irish Prime Minister Bertie Ahern called, asking the same thing. They assured me that the review would be narrowly focused and take only a few weeks. Both governments feared a resumption of the Troubles, the sectarian violence in which thousands had died and tens of thousands had been injured.

It was an extremely difficult decision. I had become deeply involved in Northern Ireland, and had come to like and admire its people. But I had been away from home for much of the previous four years. If I returned, I risked becoming involved permanently, whatever was said about "a few weeks." I talked it over with Heather, who had borne the brunt of my absence. She settled it: "You have to go back. If you don't, and the war resumes, you'll never forgive yourself." The following week, on July 20, I returned to Belfast.

The situation there turned out to be worse than I had expected. One of the pro-agreement parties had dissolved, while two new anti-agreement parties had been established. The next several days were a depressing series of meetings with the leaders of 11 sparring parties. I got an earful. Fearing a total collapse, the pro-agreement parties lashed out at each other and at the prime ministers for their inability to implement the accord. The parties opposed to the accord poured scorn on those in favor. Some even urged me to turn around and go home.

In Northern Ireland, everything slows down in August, including peace negotiations. So, after a week of preliminary discussions, I headed home to Maine, to reflect and try to devise a plan of action. I knew that when the parties met again in September there would be an initial period of venting anger. The key for me would be to figure out how and when to bring that phase to a close and move the participants into serious negotiations. Only then could I know if there was any possibility of saving the agreement. Naively, I hoped I could complete the review in two to four weeks. Instead, talks went on for nearly three months.

The absence of self-government for a quarter-century has created an unusual political culture in the North. Lacking the authority to make decisions, politicians can and regularly do take absolute, unyielding positions. Any hint of compromise is denounced as weakness or, worse, "selling out" to the enemy. And the sad, steady cycle of death, grief and retaliation has bred extreme sensitivity. As one of the delegates said to me when the negotiations began in 1996, "Senator, if you're to be of any use here you must understand that we in Northern Ireland would drive 100 miles out of our way to receive an insult."

It was a long way from the U.S. Senate, in distance and substance. I served as majority leader for six years. Bob Dole was minority leader. The two of us disagreed daily on issues, but we never exchanged a harsh word, publicly or privately. We trusted each other, and we knew that compromise is necessary if the Senate--and our democracy--is to function. We tried hard, and not always successfully, to place the national interest first. That's a message I tried to get across in Northern Ireland--that compromise need not mean failure or weakness. Rather, it could be based on strength and self-confidence, and could benefit the larger society.

Getting the Good Friday agreement signed had been difficult. But, as in so many conflicts, implementing it was even tougher. The main point of contention was this: The unionist parties refused to join in an executive (in American terms, a cabinet) with representatives of Sinn Fein, a nationalist party with links to the Irish Republican Army, unless the IRA first began disarming, or "decommissioning," as it is known in the North. In reply, Sinn Fein argued that the executive (and other institutions to be created under the agreement) had to be established first, to be followed by a collective effort to encourage the paramilitary groups on both sides to disarm.

In the political shorthand of Northern Ireland, the nationalists wanted devolution first; the unionists wanted decommissioning first. Each claimed that its position was based on and consistent with the Good Friday agreement. Neither side would budge. For almost a year and a half, there had been neither devolution nor decommissioning.

When my review began in earnest in September, it was given no chance of success. That was a fair assessment. As expected, the early meetings between Sinn Fein and the largest unionist party (the Ulster Unionist Party, or UUP) were filled with recrimination. For a month, they pointed accusatory fingers at each other. I decided that I had to do something to change the mood. We had been meeting in a drab government office building just outside of Belfast. The meetings were short--at most two hours--and were frequently interrupted as the party leaders were called out to take phone calls or meet visitors. As soon as the meetings ended, the leaders were besieged by the media, asking them difficult questions, trying to pin them down with a hundred "what-if" scenarios.

So in October, I moved the review to London. Winfield House, the residence of Philip Lader, the U.S. ambassador to Britain, is a comfortable mansion with spacious grounds and relative privacy. Instead of two hours, the first meeting there lasted two days. There were no interruptions, no deadlines, no pressure. The parties shared meals, during which they talked about their families, sports, vacations--anything but business. At my request, they agreed to a news blackout.

Gradually, the atmosphere improved. There were fewer angry outbursts, more meaningful discussions. Men who had hardly spoken earlier began to understand each other's problems. I attended all of the meetings. I brought no staff members and rarely took notes. I didn't have to. For years, I had listened to the same men and women making the same arguments. I could recite their positions in my sleep. Mostly I listened and, when I thought it useful, steered the discussion. When we returned to Northern Ireland in late October, a serious negotiation was underway.

As I listened, I began to conceive a plan of action. I told the parties that no solution was possible that fully accepted one side's argument; that would automatically make it unacceptable to the other side. Any solution had to involve pain and concessions for both. The question remained: Even with goodwill, was an approach possible that both sides might find acceptable?

I tried to answer that question in early November. I made some suggestions that would, if accepted, lead to both devolution and decommissioning and, ultimately, to full implementation of the Good Friday agreement. The suggestions also would cause Sinn Fein and the UUP to endure severe political pain. I was heartened by their responses. Delivered separately, they were almost identical: We'll try, but we don't think we can do it, because you've asked too much of us and not enough of them. I knew then that I had found the middle ground.

After several long days of intense negotiations, during which my suggestions were rearranged and modified, the parties agreed to go forward. Beginning on Nov. 9, there was a series of carefully planned statements and actions, all intended to help build the political confidence necessary to enable the parties to take the risks required for peace. I issued a statement in which, for the first time, I expressed confidence that the impasse could be overcome; the independent commission established to verify the decommissioning of arms asserted a more active role in the matter; the pro-agreement parties made assuring statements; and the IRA announced that it would appoint a representative to meet with the commission.

For me, the past week has been gratifying and hopeful. On Monday, the parties nominated ministers for the new executive. On Tuesday, the British Parliament took up devolution legislation. The process accelerated on Thursday, a momentous day on which Parliament devolved power to the new Northern Ireland Assembly; the executive of that assembly, including representatives of the UUP and of Sinn Fein, formally met for the first time; the IRA named its representative to meet with the independent commission; and Ireland's constitution was amended to delete its territorial claim on the North.

Northern Ireland's political leaders are demonstrating wisdom and courage in taking risks--political and personal--for peace. Still, difficulties remain. The parties will continue to disagree, and in both communities there are men of violence who continue to see any compromise as a sellout, and who will try to reignite sectarian war. But a major obstacle has been overcome, and with each passing day, peace is more firmly lodged.

A part of my heart will forever be in Northern Ireland. I hope to return often, and when I do, I pray it will be to a society at peace, where hope and opportunity are alive and where tolerance and mutual respect, and fairness and justice, are not distant dreams but rather the reality of daily life for all.

George Mitchell, the former Senate majority leader, was chairman of the negotiations that led to the establishment last week of a power-sharing government in Northern Ireland.