As we consider whether Australia should obtain nuclear weapons, we need to ask who might subject us to nuclear blackmail. In the authoritative statement of China’s strategic vision in President Xi Jinping’s address to the 19th Communist Party Congress on 18 October last year, the three core elements of China’s vision of the new world order were parity in China–US relations; growing Chinese influence in writing the underlying rules and in designing and controlling the governance institutions of the global order; and more assertive Chinese diplomacy in that new international system.

The world therefore should prepare for a surge in Chinese international policy activism. It seems reasonable to conclude that—regardless of who may be at fault in initiating hostilities—the possibility of a future conflict with China can’t be ruled out. At the same time, Paul Dibb and Richard Brabin-Smith argue in their recent ASPI report, Australia’s management of strategic risk in the new era, that ‘it’s difficult to imagine any other major power … attacking Australia’. And there, for ASPI’s Andrew Davies, lies the rub, because ‘China is a nuclear power’.

But it does not follow that Australia must prepare for Chinese military or political use of nuclear weapons. For eight years or so, China has indulged in bellicose rhetoric and engaged in assertive behaviour against several neighbours, stoking their fears about its motives and intentions with growing capabilities. That said, of the nine leaders with fingers on the nuclear button, whose quality of nuclear decision-making is likely to be more responsible than Xi Jinping’s? Certainly not those who boast about the size of their button.

China’s nuclear stockpile is below 300, compared to nearly 7,000 warheads each for Russia and the US. Fan Jishe argues in an APLN policy brief that—notwithstanding its massively growing economy—China has consciously refrained from engaging in a sprint to nuclear parity with Russia and the US because its governing doctrine envisages only one role for nuclear weapons: to prevent nuclear blackmail.

Despite the total transformation in China’s economic fortunes since the 1960s, its nuclear doctrine, acquisitions program, and deployment and employment policies have remained essentially unchanged. It’s the only one of the nine possessor countries to be committed fully to an unequivocal no-first-use policy. Conversely, of the nuclear nine, only the US can be suspected of harbouring designs to shift from mutual vulnerability (the basis of deterrence) to nuclear primacy (which would enable use without fear of nuclear retaliation).

Of course, we can’t simply rely on the word of a potential adversary. But there are two further considerations. On the one hand, the international reputational cost to the next country to use nuclear weapons would be very high for breaking the global taboo. The cost would be even greater for a power that has a firm no-first-use policy. And the costs have been raised still higher by the new UN nuclear ban treaty. The treaty’s primary impact is intended to be normative, not operational, as I argue in the current issue of The Washington Quarterly, through moral stigmatisation and legal prohibition. It specifically prohibits the threat of use, along with banning any actual use of nuclear weapons. Instead of welcoming the treaty as a contribution to our national security, Australia has opposed and rejected it. On the other hand, an Australia reduced to a post-nuclear-attack atomic wasteland would be of no commercial, strategic or any other value to China, so the reputational cost would come with no compensating material or geopolitical gain.

According to a careful statistical analysis of 210 militarised ‘compellent threats’ from 1918 to 2001 by Todd Sechser and Matthew Fuhrmann (Nuclear weapons and coercive diplomacy, 2017), nuclear powers succeeded in just 10 of them, and even then the presence of nuclear weapons may not have been the decisive factor. Non-nuclear states were more successful at coercion than nuclear-armed states (32% of cases versus 20%) and nuclear monopoly gave no more assurance of success. In a different dataset of 348 territorial disputes between 1919 and 1995, possessor and non-possessor states won territorial concessions at almost the same rate (35% and 36%, respectively).

Lacking compellent utility against non-nuclear adversaries, nuclear weapons can’t be used for defence against nuclear-armed rivals either. Their mutual vulnerability to second-strike retaliatory action is so robust for the foreseeable future that any escalation through the nuclear threshold really would amount to mutual national suicide.

The only purpose and role of nuclear weapons, therefore, is mutual deterrence. They are credited with having preserved the long peace among the major powers in the north Atlantic (the argument that holds NATO to have been the world’s most successful peace movement) and deterred attack by the conventionally superior Soviet forces throughout the Cold War. Yet that too is debatable. How do we assess the relative weight and potency of nuclear weapons, West European integration and West European democratisation as explanatory variables in that long peace? No evidence exists to show that either side had the intention to attack the other at any time during the Cold War but was deterred from doing so because of the other side’s nuclear weapons.