This is mostly nonsense. David Edgerton of Imperial College London remarked (in his book The Shock of the Old) on the “paradox of lethality”, with conflicts becoming less lethal even as weapons ostensibly become more so. The reason is that those on which most money is spent – hi-tech, high-profile airborne ones – are fundamentally inaccurate, and are anyway useless at taking territory. Missiles, which now include drones, seduce generals into an illusion of power, when in reality they are little more than weapons of terror. War is about holding land, not blowing up people and things.

As for nuclear weapons, Edgerton points out, they are simply too lethal to use. The craziest and most paranoid owners have not dared even to threaten them. They were no help in Vietnam or the Falklands, in Chechnya or Iraq or Afghanistan. The Chinese communists were right to call them “paper tigers”, though that did not stop the Chinese army wanting them as prestige objects.

The trouble is that no one ever sold a book or won a defence contract by downplaying nuclear holocaust. The cold war was dominated by pro- and anti-nuclear hysterics, giving no purchase to anyone accusing both sides of exaggeration. Yet every discussion of nuclear proliferation is awash in such qualifiers of doom as possible, potential, escalating towards, capable of and, most seductive of all, tipping point.