I'm a child of the 1970s and 1980s; I grew up under the shadow of the mushroom cloud. Prior to the end of the cold war in 1989-91, I don't believe I ever lived more than 10 kilometres from a strategic nuclear target. (I grew up down the road from the biggest tank factory in Europe; went to university in London: subsequently lived and worked within the blast radius of the M62/M1 motorway junction and a regional airport.)
Trying to explain the psychological effects of this period to the young is difficult—all I can do is point then at Threads. However, despite the Lovecraftian horror lurking in the background—the constant awareness that coolly calculating intellects in distant countries might at any time decide out of game-theoretic considerations to rain thunderbolts and earthquakes on my world, effectively destroying it—I was not a supporter of unilateral nuclear disarmament.
But times have changed and I'm reconsidering my position on that subject. Here's why.
The A-bomb, in 1945, must have been truly shocking; a device that could, with a single bomb, inflict as much damage as a thousand bomber raid. In an era of total war, the Manhattan Project (and its British counterpart, Tube Alloys, which was merged with it in 1943) seemed like a necessity, payback and escalation in the wake of the Blitz. For which we can ultimately thank General Douhet for his theory of air power and the [disproven] idea that shock and awe would cause civilian populations to rapidly cave in time of war.
The A-bomb promised to shorten wars by making it possible to destroy strategic targets such as weapons factories and armoured divisions with a single strike. But then it turned out to be surprisingly, dismayingly easy for other countries to build such devices. The focus switched from the A-bomb to the delivery system—first strategic bombers, then ballistic missiles, and finally cruise missiles and artillery. And in the meantime, better ways of destroying strategic targets came along: the H-bomb made possible the destruction of just about any hardened target, and then of an entire capital city. The term "balance of terror" was coined; by the time the USA and USSR began to gradually step back from the brink in the mid-1970s with the SALT arms limitation talks, the US nuclear forces were targeting individual sub-post-offices in Moscow with quarter megaton nukes.
The UK was caught in an odd position. It had proven, during the second world war, to have a vital strategic role as America's unsinkable aircraft carrier and resupply depot, moored 50 kilometres off the coast of Europe. In any US/Soviet war scenario, the UK played a critical role. Nor were the British political elite necessarily opposed to this. The Conservatives hated and feared the threat of Soviet communism; the Labour Party leadership hated and feared the Soviets even more (as first cousins once removed in the family tree of left wing ideology, they were seen as class traitors by the first generation of Bolsheviks). A post-war consensus saw the British government devote significant resources to developing nuclear weapons, and indeed the first British A-bomb test took place in 1952.
But the UK was the head of an empire in long-term decline. In 1956 the political elite in both the UK and France faced a crisis after the Suez crisis effectively slammed on the brakes on British imperial influence east of the Nile; the USA had asserted the primacy of its own interests. What to do? To paint with a very broad brush, the French response was, "we cannot rely on the perfidious Americans to back us up: we need to preserve the capability to act independently at all costs". The British response was, "we can no longer act alone without American support, so we need to preserve a good relationship with the Americans at all costs."
Prior to 1956, the British nuclear deterrent had the goal of preventing the USSR from threatening the UK by promising a nuclear counter-attack, in the absence of third-party support: it was independently built and operated, carried by the independently designed and operated V-bomber force. Their job, in accordance with established strategic bombing doctrine and the balance of terror theory, was simple: destroy Moscow. It made a certain sense, when the chief occupant of that city was a hyper-paranoid dictator with proven territorial ambitions; the point was to make the cost of direct aggression against the UK unthinkably high.
After 1960, however, the direction of British strategic nuclear thought shifted. The USSR was now run by committee, headed by a first among equals who could be deposed (as indeed Nikita Kruschev was in 1964); it was perhaps more stable and less likely to launch a surprise invasion, but deadly crises could still arise through miscalculation. Meanwhile, the significance of the Special Relationship continued to gather weight in the minds of British strategic planners. A decision was taken to replace the V-Force in the mid-1960s with a less vulnerable-to-missiles submarine force, carrying American-built Polaris missiles with British MRV warheads. And in the early 1980s, at the height of the Cold War, Margaret Thatcher's government decided to replace the aging Polaris submarines with new boats carrying the Trident D5. Again, the goal remained unchanged: "maintain the capability to destroy Moscow, independent of the United States, in order to deter the USSR from acts of aggression against the UK". (Note the "independent of the United States" clause. The constant fear of British war planners during the Cold War was that in some recondite USA/USSR stand-off, the USA might sacrifice their allies in order to avoid direct conflict with the enemy.)
And that's how things stood during the Cold War.
From my point of view as a native of Airstrip One, the existence of the British strategic deterrent didn't seem to make things significantly worse. Unilateral disarmament, though superficially attractive (was it conceivable that anyone would ever willingly use those missiles other than in a second strike? No. Would a second strike bring back the dead? No. So what's the point?), had the worrying problem that it wouldn't take the UK out of the firing line. Soviet nuclear doctrine, as we now know, saw nuclear war as a winnable battle; they expected to fight with nukes from the outset, and merely being part of the enemy alliance would be enough to draw down a tactical nuclear bombardment on the UK.
But then the Cold War ended. And we continued to maintain the Trident boats, even as the proximate justification for their existence went away. New justifications came along: we needed the capability in case a new threat emerged—a nuclear-armed China, or maybe Iraq, or even North Korea. (Leaving aside the fact that China is more interested in trade, Iraq was a paper tiger, and the UK has had no actual involvement in the Korean peninsula for the past sixty years.)
Meanwhile, it became apparent that the Vanguard boats were serving as an unofficial annex to the US Navy's Trident capability; the START treaties permit the US to operate 12 such submarines, but the UK effectively gives them another 4. The Royal Navy Trident rockets are maintained and refurbished from the same depot as the US Navy's missiles. The warheads are, according to some, built in the UK from designs supplied directly from the United States, and are effectively interchangeable with the American payloads. There are even rumours that some years ago the UK stopped independently building and maintaining warheads and now shares a common pool with the United States, complete with US built and operated permissive action links on the "British" missiles.
And in the meantime, the nature of warfare changed.
Let's remember those thousand-bomber raids and their original purpose: to put strategic targets out of operation. They were necessary because bombers were inaccurate. Horrendously so. In 1940, the RAF calculated that bombs dropped during night raids fell, on average, within 5 kilometres of their target. If that's an A-bomb, it may do some good; if it's a 500lb high explosive device, it's a joke. By the end of the war they had substantially improved their accuracy, but it still took either a huge raid or a highly trained elite squadron to put a major target out of commission.
Then came the new technologies. First LGBs; a single bomb that could take out a bridge, replacing multiple-squadron strength bomber forces with unguided bombs. Then came JDAMs. Cheap, droppable in any weather, harder to jam than an LGB. A single bomber with JDAMs could strike many targets scattered over a range of kilometres with a single pass! In the wake of the Kosovo war, which featured the first major bombing campaign mediated by stealth aircraft with JDAMs, I'm told that some bright sparks calculated what it would have taken to recapitulate the strategic impact of the RAF/USAAF 1943-45 heavy bombing campaign against Germany, and came up with the figure of: one squadron of F-117A Nighthawks with JDAMs, and six weeks, with a 50/50 probability of one hull loss.
As strategic weapons, it seems to me that nuclear weapons are obsolescent. Yes, they could do the door-breaking job of destroying factories and cities. But there are cheaper, less destructive ways of doing the same job—and the other methods are politically acceptable. Any nation that actually used strategic nuclear weapons in war-fighting these days would be a pariah state thereafter, with incalculable long-term consequences (none of them good). H-bombs only serve one purpose these days: state terrorism.
You can't use H-bombs in war. You can use JDAMs and LGBs and drones. So why is David Cameron so keen on spending £70Bn on replacing an aging weapons platform that is of no actual use to the British military and which sucks vital resources away from the bits of the Royal Navy that actually do things?
In claiming that North Korea could launch a nuclear strike at the UK, Cameron inadvertently blew the cover on why the current British political elite support maintenance of a vastly expensive nuclear weapons force. It's not to serve British interests; rather, it's to shore up the special relationship by supporting US interests. North Korea, outside of its immediate neighbours, is very much a US political shibboleth. The idea of a North Korean nuclear strike on the UK is so ludicrous as to be laughable; why would they bother, when Seoul is so much closer? (Or Tokyo, if they want to look for hated former colonial oppressors.)
The political purpose behind the drive to replace the V-class submarines is to provide a 25% boost to the US Navy's Trident force. And the thrust behind the construction of the Queen Elizabeth class Aircraft Carriers (the largest ships ever built for the Royal Navy, just as the UK is declining to clear second-rank status as a global power) is to provide fill-in support for the US Navy's carrier force, which itself appears to be in long-term decline. And if it isn't obvious to you, I'd just like to note that this is a complete reversal of the pre-1956 logic underpinning the British independent nuclear deterrent—a shift from independent capability to its opposite.
As to why this might be, it's the logic of Suez coming home to roost: having given up on the idea of a UK that can operate without US support, our political elite have enthusiastically adopted Americanophilia as an ideological assumption. If they can just be American enough, maybe the Americans will forget that they're foreigners? Something like that. It wasn't a bad idea, in the wonder years of the 1950s to 1960s, when the United States could send Navy aviators to play golf on the Moon and bestrode the Earth like an economic colossus. But the United States today is visibly recapitulating the usual path of imperial decline, losing relative advantage in a 21st century that is now clearly coming into view: hot, crowded, dense, multipolar, dominated by international capital and labour flows. The idea of the monolithic anglophone superpower is a dangerous mast to nail your colours to, if you're a small island nation that lost its empire a lifetime ago.
Anyway, this is a long-winded explanation of how I've come to change my views on the British nuclear deterrent. I think that during the 1960s to 1980s, the Campaign for Nuclear Disarmament were wrong, although I'll give them credit for idealism. But in the 21st century, I can see no convincing case for the UK retaining nuclear weapons. We should at most maintain a plutonium stockpile and a pool of expertise such that we could design and build new bombs from scratch if given a couple of years' notice, if circumstances change: but we don't need actually-existing nuclear weapons any more, and the money would be better spent elsewhere.