China’s race towards nuclear parity with the United States and Russia is transforming international strategic stability. As Washington contemplates how to address two nuclear peers, some argue the United States needs a larger nuclear arsenal than China and Russia’s combined strategic forces.

This would be a tragic mistake. An extensive nuclear buildup would reduce deterrence and security by hollowing out U.S. conventional forces. Instead, Washington must realistically assess the danger and find cost-effective methods to shore up deterrence.

As the ultimate guarantor of a nation’s security, nuclear weapons generally provide an excellent return on investment. That doesn’t mean they are cheap, however.

The United States is currently modernizing its entire nuclear force, including warheads, ballistic missile submarines (SSBNs), strategic bombers, and land-based intercontinental ballistic missiles. The nonpartisan Congressional Budget Office (CBO) most recently estimated that this effort will cost $634 billion for the ten-year period starting in 2021. By 2030, CBO projects nuclear modernization to account for 12 percent of the budget of the Department of Defense (DOD).

If China reaches nuclear parity with the United States and Russia, Washington would need to double the size of its arsenal to equal Beijing and Moscow’s combined forces. The United States and Russia currently have about 1,550 deployed nuclear weapons. In 2020, CBO estimated that building out the U.S. nuclear arsenal to 3,000 to 3,500 warheads in a survivable manner would cost as much as $172 billion just to purchase the delivery systems. That’s more than DOD’s entire procurement budget this year. Moreover, that figure excludes the costs of building additional warheads as well as sustainment costs, the latter of which could be an additional $8 billion a year (or nearly 1 percent of DOD’s current budget).

Even this is an overly optimistic assessment; matching Russia and China nuke for nuke would be much more difficult and costly. Already, supply chain issues are delaying America’s current nuclear modernization plans. The defense industrial base would struggle to double the size of America’s arsenal and non-nuclear military investments would almost certainly suffer as a result. Moreover, Moscow and Beijing would not stand idle if Washington undertook this nuclear expansion. Instead, they would expand the size of their arsenals, requiring Washington to spend even more time and resources building additional nuclear capabilities.

None of this is affordable at a time when the United States is dealing with Russian aggression in Ukraine and an unprecedented Chinese military buildup in the Indo-Pacific. Deterring China is an especially daunting challenge given the pace of its military expansion. Beijing already boasts the largest navy in the world and a sophisticated set of conventional capabilities designed precisely to deter or defeat the U.S. Joint Force. Simply put, devoting more money to nuclear weapons would leave the United States and its allies outmatched in the Indo-Pacific.

Fortunately, the United States doesn’t have to pursue this self-defeating policy. For all the talk about a “no limits” partnership, a unified Chinese-Russian nuclear attack is inconceivable for the foreseeable future. As I write about in my book, Atomic Friends: How America Deals With Nuclear-Armed Allies, combining multiple nations’ nuclear arsenals into a single force is an extraordinary challenge. At the very least, it would require China and Russia to have a unified military command.

As NATO’s experience demonstrates, this is a necessary, but not sufficient, condition. A unified nuclear force requires one nation to cede some control over its strategic weapons to the others. Given the consequences of nuclear war, even the closest allies won’t give up their nuclear buttons. In the 1950s and 1960s, the United States pushed the UK and France to put their atomic weapons under NATO command. Since NATO is led by an American general, this essentially meant under U.S. control. Although the UK nominally agreed to this, the British prime minister retained the exclusive right to decide when to use—and not use—London’s nuclear weapons. France wouldn’t even entertain the idea. No Russian or Chinese leader will give up their nuclear weapons to the other side, especially given the potential gains of sitting out a nuclear exchange with the United States.

At the absolute most, then, America’s arsenal needs to be capable of withstanding a nuclear attack from Russia or China, retaliating against that country, and still retaining enough forces to deter the other one. This shouldn’t be a problem given that U.S. ballistic missile submarines (SSBNs) remain undetectable, and—according to the Department of Defense—each one carries twenty submarine-launched ballistic missiles with multiple, independently targeted warheads. One or two SSBNs should be more than sufficient to deter the remaining adversary after a nuclear exchange.

There are also lower-cost options to hedge. As the United States acquires its new strategic bomber, the B-21, it can retain the existing nuclear-capable B-2 bombers, much as it has with the B-52, which was first deployed in 1961. Similarly, it can expand the number of bases capable of hosting strategic bombers. During a crisis, the bombers can disperse to more areas, making it difficult for an adversary to eliminate them in a first strike.

America’s land-based ICBMs can also be made more survivable—and powerful—relatively cheaply. Instead of building more missiles, the United States could simply build more silos to host them. Since China and Russia couldn’t be sure which silos had ICBMs at any one time, either country would have to expend more nuclear weapons in a first strike. Furthermore, to enhance each missile’s power, the United States could once again put multiple warheads on each missile, something it only stopped doing after the 2010 Nuclear Posture Review.

The coming era of nuclear tripolarity presents significant challenges. In addressing the changed strategic environment, Washington must find creative solutions to challenges rather than pursue costly, robotic policies that leave America and its allies more vulnerable below the nuclear threshold.

Zachary Keck is a former managing editor of The National Interest and Congressional staffer. He is the author of Atomic Friends: How America Deals With Nuclear-Armed Allies. The views expressed in this article are those of the author and do not reflect the official policy or position of the U.S. Defense Department or the U.S. government.

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