This is a test of people, not of hardware. The problem was well put on the front page of the Independent yesterday, where a Whitehall source said baldly that "Sinn Fein don't trust us and we don't trust them". Just so. The British government and the Ulster Unionists think the IRA wants to talk with cocked guns under the table.
The republicans, though, think the proposed international commission is a way to wheedle them into total surrender, stringing out the jabbering for no political gain. Yesterday the Sinn Fein president, Mitchel McLaughlin, was arguing that in all previous peace talks the agreement had always preceded the surrender of arms. He has a point. We do not trust them; but we must accept and actually feel that they do not trust us, either.
Where there is such suspicion, a suspicion worked for and earned over the centuries, true political leadership is slow to anger. It is rare for British ministers, especially Sir Patrick Mayhew, to show public irritation about foreign politicians. Restraint is his forte. And however embarrassing the last-minute cancellation of the summit was, it was foolish and self- indulgent of him to blame Dublin so openly. The government there is not only Irish nationalist; it is also an intermediary. To expect it to "deliver" the IRA is as absurd as expecting London to "deliver" Peter Robinson or David Trimble.
All of which said, there is now a real dilemma facing all sides. Though the custom of peace has been growing for a year, we have had a year of rising private frustration among the politicians, too. Guns before talks, says London. Talks before guns, says the IRA. Behind those stark positions stands a long, long inheritance of mutual mistrust. In the end it always comes down to "you first"; "no, you".
What does Britain's "you first" amount to? Is it that the IRA "surrenders" - shades of Luneburg Heath, flags cracking in the wind, stiff handshakes, official photographs? No, of course not. That all its armaments should be handed over before talks start? Again, obviously not. It would not be possible for anyone to determine whether all the arms had been surrendered; there are dripping copses in Co Meath where boxes of carefully oiled Russian guns will rest until the next Ice Age.
Instead, Britain wants agreement in principle and a beginning of the process, which need not mean the actual surrender of many weapons before talks start. But from the British point of view, it has to be more than a gesture: posting an elderly service revolver in a Jiffy-bag to the Ministry of Defence would not be enough.
Were it only a matter of gesture, things would be easier. Arms could be mysteriously "found" in the republic. In fact, that has happened already, on several occasions. A fortnight ago, arms were found at Skibbereen and the Gardai were reportedly surprised that they had been so poorly hidden. A symbol or a coincidence? A gesture from the IRA leadership or a blunder by some panicky volunteer?
No one who knows is saying. And that, without being funny about it, would be an Irish solution to this impasse. Nothing too explicit would be said about the uncovering of explosives or guns. But assumptions would be made. The politics would rumble on.
London is more empirical and thorough. Our government, speaking for the Unionists, wants clarity and timetables. The military men are also very keen on the surrender of specific arms. They want the handover of some Semtex explosive and some heavy machine-guns and missiles. That would genuinely diminish the IRA's capability to, say, demolish Canary Wharf, from where I am writing this column, or to shoot down military helicopters. Semtex is rather harder to accumulate these days than it was in the late Eighties. It may be that the IRA has got so much that it could give some up without seriously reducing its lethal capacity; but the British demand should be recognised as a serious military one, not only as a political "gesture".
Hence the current problem. The international commission was meant to be a way through, a process and not just a gesture, but turned out to be a classic example of mutual misunderstanding. John Major and Sir Patrick approved it because they thought it would lessen IRA hostility to decommissioning; it would string things out and would put the process at arms' length from the British.
In fact, after an internal argument, Sinn Fein took the opposite view and decided it was a snare. The party depends heavily on American support and patronage; to be asked by Americans to hand over weapons, and to tell Americans to get stuffed, would be much harder than dealing with the hated British. The talking would be going on, endlessly, with the Brits and the Unionists, while on the other side of the street the Americans persuaded the IRA to give up its weapons.
So, again, mutual mistrust was the problem. There is no obvious new wheeze available, no easy compromise between handing the weapons over and not handing them over. And that being so, the logical, thought-through response to what has happened in the past 48 hours is utter despair.
Yet I have discovered a curious thing. Talking to people in Ireland and London, I have found no one who knows exactly how to move the thing on - yet everyone seems relatively optimistic. Talking in this office, one of my colleagues described it as being like a cartoon when the characters walk off the clifftop and keep going for a dozen strides before they realise there is nothing below them, panic and fall.
Maybe the fall is coming. But the basic causes for crazy optimism still apply. Mr Major has more to gain by giving a little than by provoking a crisis. As happened exactly a year ago over his demand that the IRA announce a "permanent" ceasefire - something which did not happen - he has to slip off the hook of a self-imposed confrontation. If you cannot go ahead, pause and go round.
On the other side, Sinn Fein is edging towards a respectability and political clout it could never have achieved while the bombing went on.
What should happen now is - not very much. Then the British government needs to give the republicans more, perhaps on prisoners, perhaps by opening a different strand of talks unrelated to the arms issue. This is an unheroic, blurred sort of remedy to what looks like a stark choice. It is what Lord Owen would call fudge and mudge. But a year of fudge and weaselly mumble and trudging compromise have done more for the people of Northern Ireland - far more - than decades of hard-edged, hoarse-voiced certainty. A permanent peace needs to be crept up on and murmured to, not pelted with ultimatums.