A snapshot of the world’s nuclear weapons—and how the numbers are changing

A new Pentagon report offers a look at how one arsenal is shifting.
An American ballistic missile submarine received supplies from an MV-22 Osprey aircraft in August, 2018. US Navy

On November 29, the Department of Defense released its annual report on the military power of China. The document offers a public-facing look at how the military of the United States assesses the only country it truly considers to be a potential rival. Most strikingly, the report suggests that not only is China expanding its nuclear arsenal, but it is potentially on track to field 1,500 nuclear warheads by 2035.

Nuclear warheads are hardly the only measure of a nation’s destructive power, but they’re easily the most eye-catching. China already has the world’s third-largest nuclear arsenal, behind Russia and the United States. 

In the report, the Pentagon estimates China’s arsenal to currently be over 400 warheads. The Federation of American Scientists, which produces an independent assessment of nuclear forces, estimated China’s arsenal at over 350 warheads as of early 2022. Getting to 1,500 warheads by 2035 would require China to produce 85 warheads a year, every year, until then.

Nuclear numbers

China’s arsenal, while large and growing, is relatively in keeping with the arsenals of India, Pakistan, the UK, and France. More specifically, India is estimated by the Federation to have 160 warheads while France has 290. (North Korea and Israel, with 20 and 90, respectively, have the fewest.) 

These arsenals are all an order of magnitude or two smaller than the 5,428 for the United States, and 5,977 for Russia. That’s a huge change in scale, with the world’s largest arsenal roughly 300 times as big as the world’s smallest. It’s also a divide largely determined by history. The United States and the Soviet Union, from which Russia inherited its nuclear arsenals, were the first two countries to develop and test atomic weapons, and they did so in the context of the Cold War, after the United States used two atomic bombs at the end of World War II.

Importantly, the arsenals of the United States and Russia remain bound by arms control treaties, most crucially the New START treaty. While the US and Russia both maintain thousands of warheads in stockpiles or reserves, they both actively deploy roughly 1,600 warheads each. That’s comparable to the total the Pentagon estimates China to be working towards.

Throughout the Cold War, arsenal increases were driven by advances in technology and changes in strategy. More warheads in more missiles, including missiles that could carry and launch multiple warheads at once, developed as an approach to guaranteeing destruction in the face of developments around sophisticated defenses, like missile interceptors or silos hardened against nuclear attack. New technologies, like the continued development by Russia, China, and the United States of hypersonic weapons, could similarly bend arsenal design to more warheads, ensuring that the missiles launched in an attack can cause sufficient harm upon arrival. 

Launching points

Warheads are the smallest unit of a nuclear arsenal. They are, after all, the part that creates the explosions. But a nuclear warhead on its own is just a threat waiting to be sent somewhere far away. What really determines the effectiveness of warheads is the means available to launch them.

In the United States, there exists what’s known as the nuclear triad: Intercontinental Ballistic Missiles (ICBMs) launched from silos, submarine-launched missiles, and weapons delivered by planes. But even that seemingly simple triad fails to capture the complexity of launch. The United States can fire Air Launched Cruise Missiles with nuclear warheads from bombers, a weapon that travels at a different trajectory than gravity bombs or ballistic missiles.

The Pentagon report outlines China’s platforms across air, sea, and land. Air is covered by China’s existing H-6N bomber class. At sea, China has six operational nuclear-armed submarines, with development expected on a next-generation nuclear-armed submarine this decade. On land, China has both road-mobile missile launcher-erector trucks, which can relocate and launch long-range missiles across the country, and growing silo fields, capable of housing ICBMs underground.

The distribution of warheads across submarines, planes, road-mobile missiles, and silos matters, because it can suggest what kind of nuclear war a country anticipates or wants to deter. Silos are especially notable because they are designed to launch in retaliation to a first strike, like submarines, but unlike submarine-launched missiles, silos are specifically placed to attract incoming attack, diverting enemy firepower away from civilians or military command as a missile sink.

Road-mobile missiles, instead, are vulnerable when found, but can be relocated to avoid strikes like submarines and bombers, only with the added feature that they are visible from space. The act of signaling—when one nation uses the position and readiness of nuclear weapons to communicate with other nations indirectly—is tricky, but one of the signs countries look for is obvious mobilization seen from satellite photography. 

Ultimately, the increase in warhead numbers suggests a growing arsenal, though it is hard to know what the end state of that arsenal will be. Producing nuclear weapons is hard, dangerous work. Wielding them, even as a deterrent, is risky as well. 

What is certain, at least, is that the days of talking about Russia and the United States as the world’s predominant nuclear powers may be trending towards an end. Cold War arms control and limitation treaties, which halted and then meaningfully reduced arsenal sizes, were done in the context of two countries agreeing together. Reducing arsenals in the 21st century will likely be a multi-party effort.