NUCLEAR WAR

In the 1960s, an American strategist theorised that nuclear war need not be catastrophic. Now back in vogue, are the ideas of Herman Kahn mad, bad and dangerous—or a guide to avoiding annihilation?

by PHIL TINLINE

Vladimir Putin has repeatedly threatened to escalate the war in Ukraine by breaking the nuclear taboo. In June, as Russia installed tactical nuclear weapons in Belarus, he raised the spectre of a Third World War. And that was before the Wagner mutiny destabilised his position.

Western officials have been keen to emphasise that such a war may not transpire. Many suggest the risk of nuclear escalation has eased since the disastrous opening months of the invasion. In October, the German Institute for International and Security Affairs judged that Moscow’s use of its nuclear deterrent remained “careful”; others detect the restraining hand of China’s premier, Xi Jinping, in the Kremlin’s actions.

Even before the war, however, the established arms control framework had begun to fall apart. While some analysts conclude Russia would only use a nuclear weapon to deter existential threats to the homeland, there has been speculation that it might take a higher-stakes approach, “escalating to de-escalate”. Foreign Affairs magazine has suggested that this “could mean using a handful of tactical, low-yield nuclear weapons on the battlefield.” Veterans of the British defence establishment, including Peter Ricketts, life peer and the UK’s first national security adviser, suggested that if Ukraine’s counter-offensive were to bring them close to recapturing Crimea—“a humiliation so complete that it would put into question Putin’s own personal survival”— that would be dangerous territory. After a long respite, the fear of nuclear conflict is back.

Following the Cold War, the complex, nuanced theology of deterrence that had been nurtured in London and Washington largely fell away—just as, by 1998, the UK had abandoned the land- and airbased wings of its nuclear deterrent, leaving only Trident submarines. But since Russia annexed Crimea in 2014, the west has begun to revitalise this thinking. To make sense of how the Ukraine conflict might turn nuclear, experts in military and defence strategies on both sides of the Atlantic have returned to the foundational work of the 1950s and 1960s—not least one curious idea.

The “ladder of escalation” was the brainchild of an American strategist called Herman Kahn. In his book On Escalation (1965) Kahn presented a “generalised (or abstract) scenario” made up of 44 “rungs” that the world might climb to pass from crisis to Armageddon (see chart, p24). Lawrence Freedman, historian and author of The Evolution of Nuclear Strategy, notes that the ladder offers “almost thirty distinct ways of using nuclear weapons following their first use at rung fifteen”. Kahn’s conceit was to explode the idea that “escalation” would be an unstoppable rush to disaster; rather, the opening stages of a nuclear war might progress incrementally. The ladder, Freedman says, “is a very powerful metaphor”, which remains influential.

This certainly seems so in the United States. Daniel Post is a veteran of US Strategic Command, where he was involved in training and practising for using nuclear weapons; he is now a military professor at the US Naval War College, where military leaders are taught strategy and wartime decision-making. He argues that the literature of escalation dynamics is “not as fully developed as some other areas of international relations”, and that while its ideas are somewhat dated, On Escalation has its uses. Peter Scoblic, author of US and Them: Conservatism in the Age of Nuclear Terror, has found its approach useful, not least in countering panicky online reactions to the invasion of Ukraine.