"All the trends are negative ," says Bruce Blair, an analyst at the Brookings Institution in Washington "The system has deteriorated, and people are demoralised. The Russians even had alcohol in space."But those who know about such things insist that this is no laughing matter. While the Russians are less dependent on computers than the Americans, and are thus in theory less vulnerable to Millennium glitches, the risks associated with split-second decisions are a constant threat, and the continuing disintegration of the old Soviet systems means that sober heads are needed more than ever. But they will be constantly supplied with data from inside the mountain. A dedicated hotline to Moscow has also been installed.The Russo-American get-together in Colorado was organised by the two countries' respective defence secretaries because the US is so worried about what may happen in the chaos of Russia on New Year's Eve. The Americans are determined to stay both politically and literally sober as the new millennium dawns. They insist that CSSY2K will be "an alcohol-free operation" - and, yes, they will be searching the Russians' bags.

This may be diplomatically tricky, since a Russian New Year with neither vodka nor shampanskoe scarcely counts as New Year, let alone New Millennium. As one Russian noted: "Russians not having a drink on New Year's Eve - that's ridiculous. Buried deep inside the mountain, behind 25-tonne security doors which could withstand a blast of 1.5m tonnes of TNT, the centre is at the heart of the North American Aerospace Defence Command (Norad). On a previous occasion, the Russians were allowed on a brief guided tour of Norad; this time, they will be kept at arm's length, working at CSSY2K itself. A double- click will make it possible to find out more information about any given dot. What sort of missile? (The missile's heat signature tells the computer all it needs to know.) At what speed is it travelling? What are the nearest and farthest possible targets? How large is the "threat fan" - the area that might be hit? And, crucially: how many minutes until Armageddon?CSSY2K is down the road from the Cheyenne Mountain command centre: a complex that ought by rights to have Pierce Brosnan (or at least Austin Powers) striding through its corridors. On the computer screens in front of them, and on a set of huge television screens around them, a specially devised software package will allow them to monitor - more or less alongside their American counterparts - the movement of missiles and suspected missiles anywhere in the world These will appear as dots on a world map.

The sole purpose of their mission: to ensure that nobody blows the world up by mistake They will work in three eight- hour shifts, 24 hours a day. Of such slips are potential nuclear confrontations made.By the time details of the incident leaked out, the moment for panic had long since passed, and the world's nearest flirtation with nuclear apocalypse to date has never really lodged itself in the public consciousness. But today, as the wired world braces itself for the unquantifiable tribulations of the Millennium Bug, the prospect of accidental nuclear war has never seemed more real.It is therefore ostensibly reassuring to know that, at some point in the next few days, a clutch of around 20 Russian military officers will be arriving at Peterson Air Force Base in Colorado Springs, where they are due to spend New Year at the Centre for Strategic Stability and Y2K - CSSY2K, to its friends. The Russians had in fact been informed of the probe two weeks earlier, but the message had got lost in the post Moscow now says that "the wrong department" was informed. As in the best thrillers, the doomsday clock continued to tick until the apocalypse was seconds away. But this was for real.Ten minutes is the procedural deadline for responding in such circumstances. Halfway through the eighth minute, the Russian military decided that their country was not under nuclear attack.

The rocket was headed out to sea and no longer posed a threat. It later turned out that it had been a scientific probe, sent up to investigate the northern lights. There was no scary rhetoric, no escalating confrontations between nuclear powers Yet we still came within a whisker of the ultimate drama. (Fifty thousand Chechens, mostly civilians, died in the Russian assault. The West bleated occasionally, but took little serious notice. Plus ca change.) Compared with today - when Boris Yeltsin has just reminded the West, in connection with Moscow's continuing adventure in Chechnya, that "Russia is a great power that possesses a nuclear arsenal" - the international atmosphere was relaxed.

It was up to Yeltsin to decide whether the situation warranted the annihilation of western civilisation. As the radar showed the separation of multiple rocket stages, it began to look like an attack by not just one, but several missiles. On the face of it, there was no reason for nuclear panic five years ago. There was no Cuban-style international crisis which had brought us to the brink The Cold War had been over for several years. The only international event of any significance was a brutal little war that Moscow had just launched against a rebellious Caucasian republic called Chechnya. For the first time in history, the chemodanchik - the "little suitcase" containing a laptop computer, with several "nuclear option" buttons, in direct communication with military high command - was activated. It appeared to have been launched from a US nuclear submarine - capable of detonating eight nuclear bombs over Moscow within 15 minutes.