Last month, Russian President Vladimir Putin proposed extending the terms of the New Strategic Arms Reduction Treaty (New START) by one year. On Oct. 5, U.S. President Donald Trump said that “sounds like a good idea.”

But it is a bad idea. The United States needs to expand its nuclear force to deal with the growing nuclear threat from China, and it should not be constrained by a dated arms control agreement with yesterday’s superpower.

Last month, Russian President Vladimir Putin proposed extending the terms of the New Strategic Arms Reduction Treaty (New START) by one year. On Oct. 5, U.S. President Donald Trump said that “sounds like a good idea.”

But it is a bad idea. The United States needs to expand its nuclear force to deal with the growing nuclear threat from China, and it should not be constrained by a dated arms control agreement with yesterday’s superpower.

Since the 1972 Strategic Arms Limitation Treaty (SALT 1), Washington and Moscow have negotiated limits on their strategic nuclear forces. New START is the most recent pact; it was signed in 2010 and limits the two sides to no more than 1,550 deployed strategic nuclear warheads each. It is set to expire in February 2026.

Over the decades, arms control has been an important element of the United States’ strategic nuclear policy. Arms control agreements have contained the nuclear arms race, provided transparency into Russia’s nuclear forces, and helped stabilize an often-turbulent bilateral relationship. It has also enabled political support for U.S. nuclear modernization. There is a bipartisan consensus on an approach that backs both strong deterrence and strong arms control.

But there have always been problems. New START limits Russia’s so-called strategic forces, such as high-yield nuclear weapons on intercontinental ballistic missiles and bombers but leaves Russia’s lower-yield battlefield weapons untouched. This gives Russia a 10-1 advantage over the United States and NATO in nonstrategic nuclear forces. Republican senators approved New START in 2010 on the condition that the imbalance in nonstrategic forces be addressed, but no progress has been made on this front.

In addition, Russia has cheated on almost every arms control deal it has signed, including New START. On-site inspections were suspended during the COVID-19 pandemic, and Russia subsequently refused to allow them to resume, leading Washington to declare in 2023 that Moscow in violation of the treaty. In February of that year, Putin announced that he was suspending Russia’s participation in the treaty but would voluntarily comply with the treaty’s numerical limits. The United States took countermeasures, suspending participation with verification protocols, such as data exchanges, but announced that it would also continue to comply with the numerical limits.

In short, New START is already on life support.

The most important problem with New START, however, is China’s rapid nuclear buildup. When the treaty was signed, China possessed a couple hundred nuclear weapons. U.S. strategists calculated that 1,550 nuclear weapons were sufficient to deter Russia and also deal with China’s much smaller arsenal.

Since 2021, however, China has been engaged in the world’s most rapid nuclear expansion since the 1960s. It is projected to have 1,500 nuclear weapons by 2035, close to the New START limits, and there is no guarantee it will stop there.

This means that, for the first time in history, the United States will need to contend with two near-peer nuclear superpowers.

The U.S. Congress appointed me and 11 other experts to a bipartisan commission to study this problem. In 2023, we unanimously concluded that the United States’ current and planned nuclear forces will be insufficient to deal with this rapidly evolving threat.

The international security environment has greatly deteriorated since New START was signed. A U.S. nuclear force sufficient for 2010 is inadequate for the much more dangerous world that the United States faces in 2025 and beyond.

For the first time since the end of the Cold War, the United States will need to expand its nuclear forces.

Contrary to what many students learn about nuclear deterrence theory and mutually assured destruction, the United States does not plan to specifically target innocent civilians to make nuclear war unwinnable. Rather, Washington has long practiced what some refer to as counterforce targeting. In other words, the United States’ nuclear plans prioritize legitimate military targets, such as leadership, military forces, nuclear forces, and war-supporting industry.

There are many reasons for this, but the most important is that this is what most effectively deters the country’s autocratic adversaries. Putin and Chinese President Xi Jinping care less about the well-being of their citizens and more about their own lives, their regimes, and their militaries. U.S. nuclear strategy, therefore, threatens to hold at risk what its adversaries value most.

This is why China’s nuclear buildup puts upward pressure on the size of the U.S. nuclear force. As China builds hundreds of new nuclear missile silos, it is also creating hundreds of new targets that the United States must hold at risk as part of its deterrence strategy. This will require more weapons.

In theory, Washington could try to halt China’s nuclear buildup through trilateral arms control negotiations, but Beijing refuses to talk. Xi is committed to a larger nuclear arsenal and is not willing to trade it away.

In this context, bilateral arms control with Russia, like a follow-on to New START, no longer makes sense. The United States should not constrain itself in a deal with Russia while its foremost adversary, China, builds up its forces.

Critics have argued that expanding U.S. nuclear forces will simply cause Russia and China to build up their nuclear weapons in response, leading to a new arms race. Maybe it will. Maybe it won’t. But that is a secondary consideration. The primary purpose of U.S. nuclear strategy is not to avoid an arms race.

The primary purpose of U.S. nuclear weapons is to deter a nuclear war, and, given China’s rapid buildup, the United States will soon lack an effective deterrent. It needs to get that right first.

Accordingly, our commission recommended that the United States urgently prepare to upload additional nuclear warheads onto the country’s strategic delivery platforms, plan to buy additional nuclear-capable bombers and submarines, and develop and deploy additional nonstrategic nuclear weapons to both Europe and Asia.

The Biden administration acted on many of our recommendations and made the necessary preparations to upload additional warheads onto the United States’ long-range missiles. The Trump administration must follow through and expand U.S. nuclear forces when New START expires in February.

Extending New START by one year, therefore, would be a mistake. It would prohibit the United States from taking necessary steps to deter both China and Russia. These are steps that should not be put off. Our report used the word “urgent” 40 times.

In offering to extend New START, Putin does not have the United States’ best interests at heart. He does not want to see the United States strengthen its nuclear deterrent, and he is trying to forestall it.

Trump should not play along.

U.S. nuclear forces have undergirded international peace and stability for 80 years. Washington should get on with building the strategic forces that the United States needs to protect itself and its allies.