The Three Bomb Problem

We are used to a thermonuclear dyad. For most of the Cold War, Washington and Moscow commanded massive arsenals far in excess of those of other nuclear-armed states. However pre-eminent the US may have been in other ways, in nuclear terms the world was bipolar. That picture still more or less holds true. But for how long?

China became a thermonuclear power in 1967 after a series of tests at Lop Nur, on the edge of the Xinjiang desert. But it opted out of joining the global Doomsday machine, maintaining far fewer weapons than the other major nuclear powers. It also, unlike the US or USSR (or Russia) had a ‘no first use’ policy. Despite this, US nuclear war plans for many years featured an automatic attack on China in the event of a war with the Soviet Union.

As recently as three years ago, China had only a couple of hundred nuclear warheads. Since 2006, its long range nuclear weapons capability had been mostly organised around mobile ICBMs mounted on very large trucks.

But in 2021 that changed. Satellite images showed the construction of hundreds of new ICBM silos in the Gobi desert and in Xinjiang. The US government estimate of China’s nuclear stockpile grew to around five hundred warheads. The Pentagon forecasts that China may have 1500 thermonuclear weapons – still less than half the US stockpile – by 2035.

In an influential article published last April, Andrew Krepinevich argued that we are entering a new nuclear age. China, he said, is ‘upending the bipolar nuclear power system’. That world was dangerous enough, but a world of three major thermonuclear powers could be much worse. ‘In a tripolar system,’ Krepinevich argued, ‘it is simply not possible for each state to maintain nuclear parity with the combined arsenals of its two rivals.’ Any attempt to do so would likely result in an uncontrolled arms race, increasing the chances of a catastrophic war.

Think of the three body problem in classical mechanics. The interactions of two masses are relatively easy to calculate, but three are unstable and chaotic: there is no easy equilibrium. Nuclear armed states create a similar dynamic, a three bomb problem.

In a recent article in Foreign Affairs, however, Charles Glaser, James Acton and Steve Fetter argue that the danger of three thermonuclear rivals is being greatly exaggerated. Even if Russia and China launched a simultaneous nuclear attack on America, they say, the US would still be able to inflict catastrophic damage on both Russia and China.

Glaser, Acton and Fetter acknowledge that there would be no way out of a three-way arms race. But they say there is a way to avoid one. Nuclear strategy is currently based on the theory of ‘counterforce’: weapons are presumed to be targeted at the arsenals of the other nuclear states. (In reality, recent US plans are known to have included many non-nuclear targets, and it would be surprising if Russia’s haven’t too.)

Glaser, Acton and Fetter argue that the logical course for the US is to abandon the idea of counterforce targeting altogether, in favour of maintaining enough nuclear weapons to ‘damage or totally destroy an adversary’s society and infrastructure’. If this sounds grim, at least it precludes the need for an ever larger arsenal. A single US nuclear submarine can already launch enough warheads ‘to inflict the level of damage that is required for assured destruction’.

The question of counterforce (targeting enemy nuclear forces) or countervalue (targeting the society as a whole) has been a major point of contention in the history of nuclear strategy. But given the sheer destructive power of thermonuclear weapons, it’s never been all that clear what difference the targeting would make. Many nuclear command and control facilities are in or near major cities. And the US at least has never abandoned the idea of having the ability to launch a splendid first strike on Russia or China.

The State Department ordered its own study on the topic and the resulting report on ‘Deterrence in a World of Multipolarity’ was published in October. It came down on the side of those who believe the three-bomb problem isn’t worth being too concerned over. The study was led by Jon Wolfsthal, who has argued consistently that the US doesn’t need more or more powerful nuclear weapons.

According to Wolfsthal, what the US really needs is to rebuild its ‘nuclear diplomatic capacity’ to manage relations with the other major thermonuclear states. The report also said the US should ‘make every reasonable effort to reduce risks of nuclear escalation and arms racing’.

In the US, China’s new nuclear policy has been taken as proof of a sinister bid for global power. But it’s quite possible that Beijing believes something similar in reverse. The US is currently engaged in a massive nuclear modernisation programme. All three legs of its nuclear triad are being upgraded. The air force has flown test flights of the B-21 Raider, a new strategic bomber. New submarines carry warheads with MC4700 ‘super-fuses’, making them more accurate and destructive. The $100 billion Sentinel ICBM programme will see the replacement of 400 ICBMs and 450 silos in the great plains.

Writing in the strategic journal Zhongguo Junshi Kexue (‘China Military Science’) in 2019, three Chinese scholars noted the concern in Beijing that the most up-to-date US military systems threatened to give the US ‘a monopolistic strategic advantage’.

Understanding Chinese policy has become more difficult because of the centralisation of decision-making in Xi Jinping and a few advisers. But the director of the security studies programme at MIT, Maris Taylor Fravel, and two Norwegian scholars recently characterised China’s actions as a ‘response to what Beijing perceives as threatening changes in US nuclear strategy’.

In 2018, the Pentagon’s Nuclear Posture Review hinted that the US should contemplate using nuclear weapons in response to non-nuclear aggression (perhaps in Taiwan). In 2021, the UK’s Integrated Review for the first time included similar language.

In June this year, the US national security adviser, Jake Sullivan, acknowledged that the risk of nuclear war has become greater. He blamed Russia for pulling out of the New Strategic Arms Reduction Treaty in February, and China for ‘one of the largest peacetime nuclear build-ups in history’. He also said the US didn’t need to increase its nuclear arsenal to outnumber the combined total of Russia and China. The message was already clear that ‘any arms race with the United States is counterproductive at best, and destructive at worst.’

The US and China held arms control talks in Washington last month. But nuclear diplomacy of the kind that Wolfsthal recommended has eroded as the major arms control agreements of the Cold War have broken down. The US presidential election next year is likely to feature competitive fulminations on the need to confront China. Away from the madness of nuclear strategy debates is the reality of a new generation of nuclear weapons. In all likelihood the US will continue to seek nuclear primacy behind a screen of superficially reasonable rhetoric.