But this is not the time for despair. However easy it may be to find reasons to feel depressed at the prospects, it is more important to see what has been achieved.
Above all, there is an aspiration for change. The widespread pessimism in Northern Ireland is combined with an explicit desire to live in a world where things would be different. That wish is in itself a powerful factor. The politicians who have made brave compromises have done so partly in response to the pressures in a society where enough violence is finally recognised to be enough.
The philosophical gulf between the two sides remains enormous. Even here, however, there are the glimmerings of mutual understanding. Gerry Adams and David Trimble both know that inflexibility is not necessarily personal. They understand that there is a constituency out there which may be even more unforgiving than their immediate opposite number seems to be. In other words, both sides know that the room for manoeuvre is genuinely limited. That understanding, in itself, implies the knowledge of the necessity for compromise, at least somewhere down the line.
The talk of seismic shifts this week is more than just Downing Street spin to keep a dying peace process alive. The head of the decommissioning body in Northern Ireland, General John de Chastelain, is remarkably upbeat in his report published yesterday, with reference to the "clear intention" to decommission arms.
The problem of "sequencing" - finding a way past the apparently insoluble problem of timing, where neither side wants to be seen to jump first - still lends itself to fudge. Fudge has become a dirty word in the lexicon of Northern Ireland politics. In reality, fudge offers enormous possibilities, in that it implies an element of trust on both sides.
Trust that has been lacking for all these years. It is lacking still. But the two men who only a year ago could not bear to look at one another, let alone shake each other's hands, are now partners in an extraordinary project. Both of these men are acutely aware of the historic responsibility they bear.
Much bad news is yet to come. It would be little short of a miracle if the Orange Order march at Drumcree tomorrow passes off without any violence. As in previous years, the defiant confrontation means that an explosion of some kind seems almost inevitable.
But we must not forget how extraordinary it is that we have got this far. Two years ago, it would have seemed impossible to contemplate David Trimble, the intransigent Unionist, sitting together with representatives of Sinn Fein. Equally, an explicit suggestion from those connected with the IRA that the gun should be removed from Northern Irish politics for ever would have seemed in the realm of fantasy.
However much mutual recrimination we still face, that progress should be welcomed. In real terms, Sinn Fein has offered to ask the IRA to render all its weapons unusable within less than a year. In Northern Irish terms, this is a quantum leap, and should be recognised as such. One can understand that David Trimble still feels concerned that the start of this decommissioning - at the end of this year - is too late. But one reason why the Unionists have been so disconcerted by the offer is precisely because they see that it changes the political landscape.
For the moment, the political wind is behind Sinn Fein, who have shown themselves able to make concessions that nobody expected. The initiative lies clearly in the Unionists' hands, divided as they are. But Sinn Fein could gain diplomatic brownie points at little additional cost. Having taken the step in principle of publicly announcing that weapons can be given up, it has already gone well beyond conventional dogma. Once the willingness in principle is there, the date is, in comparison, a mere detail.
In that respect, Sinn Fein has everything to gain, and nothing to lose, from going one step further, by persuading the IRA to give up some of its weapons with immediate effect. Not in response to pressure from the Unionists, which has always been the ultimate republican no-no. The Unionists have been so wrong-footed by the latest offer that they are able to put little pressure on Sinn Fein. Instead, by making it possible for the decommissioning of arms to take immediate effect, the leaders of Sinn Fein would find themselves in the unwonted position of presenting themselves as genuine statesmen, not just as terrorists reformed.
The Unionists would be doubly confused. But the peace process would be given the final boost that it clearly needs. It may still seem a step too far. But many of the changes in the past year, or even in the past week, have also seemed a step too far. In the end, it is a matter of belief. Northern Ireland must never look back.