It is a remarkable achievement. There is now in place an agreement that could bring a permanent peace to this island of ours, that many people did not believe would be achieved.

Interviewed by RTE's Joe Duffy, Seamus Mallon described this as a unique moment. He commented on the disbelief of the participants as agreement edged closer during the early hours of yesterday morning.

Most poignantly of all he talked about the reactions of the negotiators as it became clear the agreement would be reached - tears in their eyes, handshaking and embracing. A realisation of the potential of the agreement and the benefit of it for everyone on the island.

Everyone involved deserves the highest praise. The negotiating teams have stuck with the task even though they, at different times over the last week, had excuses to walk out. In the past they might have taken those opportunities, they might have continued the jockeying for position - the politics of gesture. The Taoiseach, Bertie Ahern, in particular, has shown his commitment to peace. On the morning of his mother's funeral he was in Stormont negotiating and within hours of her burial was back in Stormont again. His participation should not be understated; not only is he the leader of our Government he is one of our cleverest and most able negotiators.

The imposition of a deadline by Senator George Mitchell also helped to concentrate the mind. It was a master-stroke because it told the people of Northern Ireland their political representatives had been given enough time to argue, to score political points off one another. It told the people that if their representatives were serious about achieving peace now was the time for them to put up or shut up. And it made clear to the talks participants that the people they represented knew this.

In a way it forced the politicians to go back to first principles, to pay attention to what their constituents really wanted.

If anyone was in any doubt about the aspirations of the people of Northern Ireland the interviews carried by the various media over the last week should have clarified that. Whether it was schoolchildren or teachers, farmers or factory workers, the first thing they all mentioned was peace. After that they would move on to what they did not want to give up, but the first words out of their mouths were about peace.

In the middle of all this tearful euphoria it is vital that we understand what has been achieved. It is a giant leap, a unique moment, a most remarkable day in political life. A huge first step. But it is just that, a first step. The next stage of the process, the selling of the agreement before the referendum will be even more important. With the Sunningdale power-sharing agreement we have seen how short-lived deals in the North can be.

I use the word "selling" advisedly. Good salespeople know if they have to sell something big, something expensive or something complex some slick wordplay won't do the job. They have to find the benefits to the purchaser of what they are selling and make sure he or she understands them.

Our politicians are going to have to find benefits for their people of signing up to the agreement and explain those benefits as clearly as possible. They are also going to have to be wary of one of the temptations facing salespeople: rubbishing the opposition.

This agreement cannot be sold on how "we beat the other lot". What has happened in the last few days is the exact opposite of that. The various sides actually co-operated. They worked together to find solutions to their problems. Implacable enemies found it in their hearts to trust each other.

To return to the negative politics that we now have the opportunity to leave behind would be both a tragedy and a travesty. The accord we have is a fragile one which would not survive the stress of accusations and recriminations.

One area for concern is the progress, or lack of it, that has already been made on selling the agreement. The SDLP, the smaller loyalist parties and Sinn Fein have been keeping their membership up to date on the progress of the talks and have plans in place for the next stage of that orientation process.

By contrast the UUP seems to have made little or no effort in this direction. This is particularly worrying as David Trimble is the leader of the seemingly most fragmented support at the negotiating table. He also represents the largest single bloc of unionist voters. Without them the process will fail. With them it has every chance of succeeding.

One of his key problems will be dealing with the word "compromise". For so long the unionists have stuck by the phrase "no compromise". It has become a word signifying weakness and capitulation. He will have to characterise the achievements of his party at the negotiations using terms like understanding, agreement, bargain and pact.

Oddly, one of the most bizarre scenes from Thursday is one of the most hopeful. Ian Paisley's public relations stunt, appearing 10 minutes before the deadline, rang hollow. But it showed his breed of politics is on the wane. The reaction from across the political spectrum was that this was a desperate act. He realised, too late, his place should have been at the negotiating table, representing his people, searching for the peace they want.

Instead he had chosen to remain outside, gambling that the negotiations would fail and he would be the only unionist representative not tainted by having to try to make a deal with the nationalists. But he had misread the prevailing mood. He had listened for what he wanted to hear and ignored the realities of what was being said. If the peace process is handled correctly his voice will become a lonely, if loud, one from the political past of this island.

For the sake of future generations on this island we must, as a people, have the courage to accept change, embrace it and make it work so that both traditions can at last live together in peace.