Ian Bruce considers the implications of the demise of second-line atomic striking power.

THE RAF's 45-year-old role in superpower confrontation came to an official end at midnight yesterday. Fortunately, for all concerned, it came with not even a whimper, far less a bang, as several hundred free-fall nuclear bombs were quietly consigned to the scrapheap of Cold War history.

From today, the Royal Navy's 58 Trident missiles become the UK's weapons of last resort or ultimate retaliation and the RAF bows out of the big time, ironically in the same week as it celebrates the 80th anniversary of its formation.

For more than three decades, at least one aircraft in each squadron assigned to the strike role always had a nuclear bomb slung beneath it and a crew on 15 minutes' standby for what would inevitably have been a one-way mission over Soviet-held territory.

In nuclear terms, the WE177 weapons assigned to Tornado GR1 bombers and designed to be delivered suicidally at low level were rendered instantly obsolete when the first Polaris ballistic missile submarine went on underwater patrol in 1969.

The nature of warfare had changed and the era of the manned strategic bomber was over. The growing effectiveness of anti-aircraft defences made penetration of enemy air space a near impossibility. It just took 30 years to admit it.

The whole charade was maintained on the pretext that Tornados flying out of East Anglia would launch tactical strikes on Warsaw Pact troop and tank concentrations in East Germany and Poland as the Soviet-led juggernaut rolled west to kick-off the Third World War.

Their bombs, currently stored in bunkers at RAF Marham in Norfolk and RAF Honington in Suffolk, are to be decommissioned and recycled over the next five years. Material from some may be used to manufacture warheads for Trident in a fissionable version of passing the baton. The demise of second-line atomic striking power comes, appropriately, on April Fools' Day. For it would be a foolish government indeed which failed to recognise the writing on the wall for even first-line armament, built to devastate continents and deter aggressors from the ocean depths half a world away.

Trident, and Polaris before it, were the hardware of Armageddon in a century which had already experienced two world-wide conflicts. There is an argument for claiming that their very existence helped prevent a third.

But post-Cold War reality and the disintegration of the Soviet Union look like spawning wars of the brushfire rather than multinational variety. The millennium seems destined to be marked by a never-ending series of ethnic, religious, and resource-led clashes. Civil war may have replaced world war as the in-thing for the 21st century. All of which brings into question the value of possessing an expensive system capable of global destruction when most wars in the past 50 years have been fought with the basic tools of rifles, machine-guns, and artillery.

Britain has three 1600-tonne Vanguard-class Trident boats already in service and a fourth nearing completion. It has so far bought 58 American D5 missiles at about #13m apiece and is in the process of building warheads for them.

Labour's pledge is that the Trident fleet will carry no more of these than the redundant Polaris flotilla which preceded it. That means deployment of at least 192 warheads, each eight times more powerful than the bomb which destroyed Hiroshima. No boat will carry more than 96 at any given time, although naval sources claim that up to 300 operational warheads will be produced on the basis of having a margin for insurance.

Each missile is tipped by a ''bus'', a nose cone vehicle which holds six genuine warheads or decoys. In the heyday of the superpower confrontation, this MIRV'd arrangement (multiple, independently-targeted re-entry vehicles) was supposed to guarantee that even against the formidable Soviet countermeasures and air defences, enough ''throw-weight'' would penetrate to turn the target area into fused glass and ruin the Politburo's entire day. Labour also says it will maintain the Trident deterrent only until it can be bargained away multilaterally in return for concessions and cuts in strategic firepower from the other members of the nuclear club. In the meantime, crewing, maintaining, and operating the four boats will cost the British taxpayer something close to #200m a year.

The system itself and its infrastructure on the Clyde at the Faslane submarine base cost about #11bn, including design and construction of the boats at Vickers' yard in Barrow-in-Furness, Cumbria.

The Navy has been exploring ways of maintaining its credibility by advancing proposals for scaling down Trident's punch by deploying smaller, tactical warheads which might still be delivered with pinpoint precision from thousands of miles away. But they are fighting a rearguard action. In the absence of a major external nuclear threat, no British Government could or would authorise a strategic strike on a Third World country. No Government could survive the political, never mind radiological, fallout. The sledgehammer v walnut argument seems set to win the day.