Why do I find it hard to share in the general euphoria over Northern Ireland? No one likes to be a pessimist. In some respects the new arrangements are what many of us have long advocated, similar in parts to those put forward by the Cadogan Group in its first pamphlet, Northern Limits (1992). What, then, is wrong with the Stormont Agreement?

Three things: first, the circumstances in which agreement was reached; second, the rewriting of history and the debasement of language involved, and third, the entrenching of the myths and misconceptions which underlie the divisions in Northern Ireland.

No democrat can be happy with the degree of appeasement which underlies the agreement. The pursuit of a settlement inclusive of the representatives of terrorism was based on the belief that the terrorists could not be defeated. The new consensus has been to persuade the terrorists to move away from terrorism, to negotiate with them, to treat them with a measure of respect, almost as honourable enemies to be accommodated. This is appeasement.

If peace can be achieved, even with a measure of appeasement, then it is worthwhile. This is the strongest argument for the Belfast Agreement. It still leaves the appalling truth that a small subversive group ready to employ ruthless terror against the civilian population cannot be defeated in a democratic society where it commands only tiny minority support.

The argument is that peace has been bought, and that the price paid in concessions has been modest. Republicans have settled, not for a united Ireland, but for a place in the sun, prisoner release, and seats in a partitionist executive.

But part of the price has also been a blatant rewriting of history. The distortion of events and of language that is now deemed a necessary part of the "peace process" is worrying. Terrorists are not required to surrender arms, but (eventually) to "decommission" them. "Decommissioning" is a term coined to accommodate the IRA's assertion that it is a legitimate army fighting a war. Its representatives talk of "decommissioning" only in terms of "demilitarisation", within which they include the withdrawal of British army units. "Decommissioning" will be part of a negotiated settlement within which both sides can reasonably claim moral authority.

They also talk of "equality", presenting their terror as an armed struggle in pursuit of an "equality" which has been denied them, and by implication, all nationalists. The agreement, with its vague use of the term "equality" and the ill-defined concept of parity of esteem, again surrenders terminology to the terrorist. In what sense has equality been deliberately denied to anyone in Northern Ireland in recent years? As John Hume repeatedly said, there was no cause in Northern Ireland worth a single life.

Much of this has been described by defenders of the agreement as necessary nonsense, rhetorical concessions to terrorists in return for de facto surrender. Maybe so, but it still leaves more than a bad taste in the mouth. It rewards the terrorists for agreeing to stop using terror, and by implication accepts that they had a right to use it in the past. This is not just morally distasteful, it is paying Danegeld.

The third worry goes beyond appeasement. When the Cadogan Group published Northern Limits in 1992, its proposed solution was based on one key foundation. This was the acceptance, by all, that partition was not the root cause of trouble in Ireland, but an inevitable if untidy means of resolving the fundamental unionist-nationalist division. Any solution, therefore, had to lie in the direction of accepting partition, and seeking to ensure that all could live with it in equity and contentment.

Such an approach goes beyond the consent principle only to the extent that it accepts that consent to Irish unity is not forthcoming in the foreseeable future, and should therefore be off the agenda. But southern Irish politicians will not do this publicly, and the State will not do it officially. This is a fundamental weakness of the agreement.

The new Articles 2 and 3 were meant to end the territorial claim. But they remove only the explicit claim, leaving an implied one, and much of the nationalist myth on which it is based. The name of the State remains "Ireland", an implicit claim to the island. The Irish nation is defined as everyone born on the island, and the sovereign right of this Irish nation to choose its own form of government is asserted. This is the language of traditional nationalism, ignoring reality and asserting the right of the Irish "nation" to ownership of the island.

Northern Ireland is now deemed to be divided between unionists and nationalists, and these two tribes must have equal say in everything. This is not a question of equality before the law, or of freedom of religion, or respect for cultural identity, all of which already exist, but of equality between the political stances of unionism, accepting and supporting the existence of Northern Ireland, and nationalism, rejecting its fundamental legitimacy and seeking to dismantle it.

This is no foundation for a stable settlement, rather it is a device, a fudge, to gain some breathing space, and bequeath the problem to others.

Many of us who voted for the agreement did so with misgivings, but in the hope that the compromises and concessions it contained would enable extremists to come to terms with the wrongness of their methods, and the discrediting of their political beliefs.

So far, this has not happened. Prisoners are released with no public - or private - admission that they were rightly imprisoned for appalling crimes. Spokesmen for terrorism are about to take their seats in government while terrorist organisations retain their subversive structure, their illegal arms and their selective use of terror.

In the near future it may be possible to look back on the past 30 years and reflect that it was tragic but necessary that so many had to die so that "inclusiveness" and "equality" could be achieved. That would be a ghastly misreading of history, taken verbatim from the Sinn Fein script. It has been said that those who ignore history are forced to relive it. What happens to those who distort it? PreGood Friday terrorism is being "decriminalised", and the erroneous lesson drawn from recent history will be that the IRA emerged undefeated, that the "armed struggle" produced medium-term political victories.

This, plus exhaustion, may produce two or three years of comparative peace in Northern Ireland. But it may leave unimpaired the cult of physical force in Irish nationalism. What happens when the euphoria wears off, and republicans realise that they are still living within the United Kingdom, on a partitioned island?

It is time for both governments to start saying publicly that Sinn Fein/ IRA did not win, that by accepting the legitimacy of Northern Ireland in the agreement they abandoned not just the armed struggle but their whole justification for it. The real test must be the surrender of arms.

The agreement says all parties reaffirm their total and absolute commitment to exclusively peaceful means, and their "opposition to any use of force or threat of force by others . . ." The existence of a paramilitary organisation holding illegal arms constitutes a very real threat of force, whether it is on ceasefire or not. All parties to the agreement are committed, therefore, to opposing the existence of the IRA (or the UVF or the UDA), and to seeking the surrender of their weapons, not as part of any general "demilitarisation" but because failure to do so is incompatible with participation in the agreement.

Dennis Kennedy, a former deputy editor of The Irish Times, is a member of the Cadogan Group.