Leading Article: Ideal, no. Hopeful, maybe. Start talking, Mr Trimble

What an outbreak of coyness there was yesterday in Belfast. There was Gerry Adams, simpering like a pupil at Madame's dancing academy. Yes, I would dearly like a Unionist partner for the Mitchell quadrille, and no, those nasty, wicked men with their guns and balaclavas, nothing to do with political me. And there was David Trimble, behaving like a push- me, pull-you. Pushed in the morning by the joint British-Irish government statement on the talks, he pulled back later, only to push again in further conversations with Senator Mitchell, making it appear only a matter of time before he too took his partners into the Stormont waltz.

But each of these characters knows very well that talking about the future of Northern Ireland is no light matter: lives and livelihoods depend on the talks continuing, let alone on their moving to some fruitful outcome. Yet it is hard sometimes to keep an entirely straight face as the protagonists pirouette and stretch, ever anxious to present una bella figura to their domestic party audiences while appearing statesmanlike and mature when the eyes and cameras of the world are upon them.

No one should pretend there is some kind of moral equality or political equivalence between Sinn Fein and the Ulster Unionists, strive as Gerry Adams and Martin McGuinness do to present themselves as coevals. They have been admitted to the talks on sufferance and on trial, because it has to be recognised that they do represent a shard of Irish opinion and a force to be reckoned with. The gamble of any talks process is that they are capable of real negotiation. There is enough hope and some hard evidence to make it a gamble worth taking.

And that is why David Trimble's continuing absence is a mistake, and a matter for regret. As long as he is not there he allows the Republicans to put themselves forward as good-faith negotiators. But making the extremist Irish nationalists look good is only one of the reasons why the Ulster Unionists should bite the bullet and decamp to Stormont. Let us briefly rehearse why they should be planting themselves in those empty chairs as soon as prickly pride allows them.

Yesterday's British-Irish government statement did represent a concession. To that extent it changed the environment within which these talks are to take place. Mr Trimble and his party colleagues are obliged to respond. The text of the joint declaration is worth close exegesis. It says the two governments would "like to see" decommissioning taking place during the talks. That's a watery phrase, to be sure, but it contains a nugget. It is not just that the unionists are being empowered to ask - a week, a month into talks, as agenda items are taken - for the signs of arms being given up. Rather, they are being invited to ask the respective governments to produce evidence of disarmament.

This puts Bertie Ahern, in particular, on the spot. He has hereby given a hostage to fortune, by implicitly committing the prestige of the Irish state to discovering signs of extremist disengagement. But is it naive even to talk positively about decommissioning, given the statement made by the IRA in Dublin in their propaganda sheet last week? The terrorists, it is said, will not give up their weapons now, or, by implication, at any point short of a settlement acceptable to the IRA. Since the IRA's ostensible ambitions for the island of Ireland involve a decimation of the population, authoritarian rule, and a return to the economic Dark Ages, "never" may be the most appropriate word here. And yet. The extremist republican movement is not a monolith; the political leadership does possess some powers of persuasion; the killers and bombers depend, to some extent, upon propitious political circumstances to replenish their ranks. Nationalist movements do change.

A newish term of art in Northern Ireland is "confidence-building". It has a warm ring to it, implying trust grows spontaneously as people meet and talk together. In fact it is a phrase borrowed from the lexicon of the Cold War where it had everything to do with verifiability and nothing to do with vodka-fuelled evenings in a Berlin bierkeller. David Trimble is thus entitled to say that his confidence will not depend on seeing the visages of Messrs Adams and McGuinness around a table but on the numbers of Armalite rifles destroyed by the Garda and the RUC. What he has to decide this week is whether the talks process is more or less likely to lead to that kind of confidence-building. It would be naive to be any more than cautious about the prospect. But as long as there is a finite calculation to be made which says peace, durable or temporary, is more likely as long as the talking goes on, Mr Trimble owes his party and his province nothing short of dogged attendance at Senator Mitchell's deal table.