The Doomsday Clock is an interesting idea. Created in 1947 by the Bulletin of Atomic Scientists it seeks to signify, in a clear and simple way, how close we likely are to nuclear conflict. Midnight stands in for High Noon. It started life at seven minutes to midnight but lost four minutes in two short years when the Soviet Union became a nuclear power. You then see oscillations over the next 65 years, centred around -9 minutes or so, as various geopolitical crises and ententes dial the minute hand back and forth. We’ve only ever got to 17 minutes away (Gorbachev’s work in 1991). Notwithstanding that the UK’s own defence budget only stretches to a small part of the global nuclear arsenal, how would renewing Trident affect that clock?

B. H. Liddell Hart, in his book Deterrent or Defence, argues that the Romans got it wrong, or at least not quite right. Their “If you wish for peace, prepare for war” should be replaced with “If you wish for peace, understand war”. In a nuclear age, where you simply don’t have the luxury of learning from your mistakes, this seems wise. In both the EU and Trident debates, however, we seem to be ignoring the signs that the cold war world – nuclear superpower versus nuclear superpower – is returning or has returned. That’s not to say that new challenges such as the rise of Islamist terrorism don’t also require new approaches. But it seems increasingly wrong to say that the world has shifted away from potential inter-superpower nuclear confrontation. So to the argument that Trident is a weapon of the cold war, the response must surely be: yes, exactly.

Russian aggression in the Ukraine – an attempt to change international borders through force; the state-sponsored assassination of an individual on British soil using nuclear poison; the repeated need to scramble RAF jets to escort Russian bombers away from UK airspace or areas of interest; Putin’s 40 new inter-continental ballistic missiles… all point to the idea that something like the cold war is still with us. And arguments of the line that the US would always protect us and other NATO members miss the point. A folding of the UK’s nuclear capability together, god forbid, with a Brexit completely undermine what Churchill called his double-barrelled strategy – negotiation from a position of strength. Putin is already steadily stealing inches if not miles and he would only be emboldened by a withdrawal or downgrading of the UK’s nuclear capability. It’s worth re-emphasising the significance of nuclear weapons in the theatre of war and the prospects for peace:

“In the field of astronomy, the concepts of Ptolemy, long predominant, postulated a central Earth around which other bodies, including the Sun, revolved. Within this structure of analysis the task of accounting for observed facts required more and more convoluted explanatory hypotheses. Copernicus however espoused a different idea of great simplifying and clarifying power: that the Earth revolved around the Sun. Once this was grasped, much that had seemed perplexing or enormously complex now fell into place. A good deal of commentary about nuclear weapons – some of it from distinguished figures – long remained of Ptolemaic character. It is important to grasp the nuclear equivalent of the Copernican perception.

The sudden and enormous leap in destructiveness brought by the advent of nuclear weapons was of a different order from that caused by, say, gunpowder or aircraft. It is not enough to view it as merely the ghastly intensification of the human horror of war. It did something fundamental at a colder level of analysis. It carried the potential of warfare past a boundary at which many previous concepts and categories of appraisal – both military and political – ceased to apply, or even to have meaning.” Thinking About Nuclear Weapons, Michael Quinlan

It seems improbable, then, that we could characterise ourselves as operating from a position of strength if our main negotiating partner wields the military equivalent of the Copernican Revolution alone. As Churchill put it: “I do not hold that we should rearm in order to fight. I hold that we should rearm in order to parley.”

All of this assumes acceptance that deterrence in the form of mutually assured destruction is effective and is a sensible strategy. For balance, it’s worth acknowledging that we can’t provide empirical evidence that nuclear deterrence works. That’s the problem with nuclear war, you can’t collect the data and learn from your mistakes. Though I recognise that some will continue to believe that a unilateralist, pacifist approach is the right one, it’s very difficult to reconcile this with Putin’s antics even in the face of a relatively unified deterrent. To draw on the lessons of the most recent world war, imagining a pacifist approach to a Hitler armed with nuclear weapons seems absurd.

So, despite the expense – and £41 billion does indeed buy a lot of schools and hospitals – we should recognise that to continue operating in the upper part of Maslow’s hierarchy of needs there’s quite a big, ongoing maintenance cost for the base, for security. As Michael Quinlan puts it, though “There is a wry irony about the costs of nuclear weapons. For what they can uniquely provide in contribution to preventing major war they are cheap, not expensive.”