The alternative to American leadership is proliferation and war.

If the American people do not want to make the effort needed for an effective defense of their allies, they have two options: they can accept Chinese regional hegemony or tolerate (or even encourage) some proliferation of nuclear weapons to US allies and partners. I outlined the demerits of the first earlier.

Some of the demerits of the second are well known. A world in which more states have nuclear weapons is probably a considerably more dangerous one. Although some prominent scholars have argued that general nuclear proliferation would produce a more stable world, this idea has had little purchase outside the academy.54 A world in which many states have nuclear weapons might contribute to deterrence among them, but it would also contain more, and more complex, relationships among nuclear weapons states, more opportunities for accident or error, and more drivers for cataclysm. Whereas general proliferation might promote some level of stability, then, it would come at an extraordinarily high level of risk.

And widespread proliferation might not prove as stabilizing as these scholars have suggested, because it might not be quite as potent a deterrent as its advocates think. It is true that nuclear weapons introduce a fundamentally different level of caution for any prospective attacker, but they do not wholly suspend the rules of logic and reason. States that have nuclear weapons facing a nuclear-armed opponent know that the surest way to invite the most devastating nuclear blow is to launch a nuclear attack. They have the most powerful reasons to avoid such an outcome, even when their territorial integrity is at stake. In other words, even a state at risk of invasion has the strongest incentives to avoid a nuclear reprisal; occupation or even conquest, especially if partial, may be preferable to destruction. This is especially so when a small state faces a large one, such as China, that has a larger and more sophisticated arsenal and likely significant missile defense capabilities.55 This dynamic is only more pronounced when what is at stake is the partial loss of territory or autonomy; nuclear war may be a tenable option when the alternative is total devastation or enslavement, but less so when it means the loss of a few provinces or submission to hegemony.56 Nuclear weapons are not, therefore, a panacea. Their proliferation would complicate and hamper China’s ability to establish hegemony over the Indo-Pacific but would not necessarily defeat it.

That said, selective nuclear proliferation might, rather than supplant the antihegemonic coalition’s defense, strengthen it, in particular by making the binding strategy more effective. This could be especially relevant if China were able to attain commanding conventional military superiority over the coalition or important parts of it. In such an eventuality, a binding strategy confined to conventional forces might not suffice, since China might be able to overcome even a consolidated coalition conventional defense and pick apart its members.

Coalition members might then turn to the United States to compensate for this conventional military inferiority with the threat of first use of its nuclear forces. Because China would have immense ability to respond to US fi rst use with nuclear reprisals against the United States itself, however, Americans would have the most powerful reasons for restraint. China might reckon that it could induce US nuclear restraint while salami-slicing away Washington’s Asian allies and partners.

Selective nuclear proliferation to such states as Japan, South Korea, Australia, and even Taiwan might help bridge the gap between regional conventional defeat and US willingness to employ its nuclear forces, especially at scale. In this world, Chinese victory in a conventional war against the United States and its allies might transgress the interests of one of these nuclear-armed regional allies enough to prompt its nuclear use against China to defend its territory. That would likely trigger a Chinese response, including against US forces fighting alongside those of the embattled ally, which in turn would be more likely to catalyze American nuclear use to prevent the full collapse of its allies’ position. Such a posture would likely make the anti-hegemonic coalition’s deterrent posture more formidable. Indeed, selective nuclear proliferation of this sort to the United Kingdom and France is judged by many to have contributed to NATO’s deterrent posture during the Cold War, when the Soviets enjoyed conventional superiority in Europe. This is, in fact, NATO’s official stance.57

Nonetheless, the perils of proliferation make this option a last resort. Far preferable is an effective conventional defense backed by, but not primarily reliant on, the nuclear forces of the United States. That standard will be hard and costly to attain, and it will require sustained focus and discipline—but the alternatives are worse.