Nuclear Arms Control Dies After 60 Years—What Happens Next?

For the first time in over 60 years, there are no binding restraints on the world's largest nuclear arsenals. The New START treaty expired on February 5, 2026, ending the last agreed limits between the United States and Russia on strategic nuclear weapons.

This isn't just about numbers—it's about the unraveling of a system that has kept nuclear competition predictable since the Cuban Missile Crisis.

The Safety Net That's Gone

New START wasn't just a cap on 1,550 deployed warheads per side. It created a comprehensive transparency framework: on-site inspections, data exchanges, limits on delivery vehicles, bans on interfering with satellite monitoring, and a joint commission to resolve disputes.

Now that safety net has vanished. President Trump rejected Putin's proposal to maintain existing limits while exploring new options, instead pushing for a "better" deal that would include China's rapidly growing nuclear force and Russia's large arsenal of tactical weapons.

But no negotiations are underway, and the administration hasn't offered to discuss any U.S. weapons systems that worry Russia and China.

The Three-Way Problem

What makes this moment uniquely dangerous is China's entry into the nuclear big leagues. While Beijing's arsenal remains much smaller than Washington's or Moscow's, it's expanding rapidly. We're facing the prospect of an unpredictable three-way nuclear competition for the first time in history.

Nuclear agreements provide four critical benefits that are now at risk:

Predictability prevents worst-case planning that drives buildups. Transparency through inspections and data sharing builds mutual understanding. Reduced first-strike incentives come from limiting particularly dangerous weapons. Improved relations flow from the simple fact that your adversary is willing to restrain the nuclear forces aimed at you.

The Kennedy Lesson We're Forgetting

After the 1962 Cuban Missile Crisis, President Kennedy realized that relying on nuclear deterrence without agreed restraints is simply too dangerous. He moved quickly to negotiate the Limited Test Ban Treaty and established the U.S.-Soviet hotline.

Every subsequent president has pursued nuclear arms control. The results speak for themselves: more than four-fifths of the nuclear weapons that once existed have been dismantled. As Secretary of State Marco Rubio has acknowledged, these agreements "left the United States safer."

Buildup vs. Restraint

Washington faces intense pressure to expand U.S. nuclear forces to deter both Russia and China. The U.S. has hundreds of nuclear weapons in storage that could be deployed, plus empty missile tubes on submarines that could be refilled. New weapons like nuclear-armed sea-launched cruise missiles are in development.

But is more really better? The U.S. already has over 1,500 deployed strategic nuclear weapons undergoing major modernization. If America builds up, Russia will respond in kind, and China may accelerate even further. Once a three-sided buildup begins, its momentum becomes much harder to reverse.

The Economics of Nuclear Competition

Ironically, all three powers have strong reasons to avoid an unrestrained nuclear race. The U.S. nuclear modernization program is struggling with enormous delays and cost overruns, and the industrial base isn't prepared for major expansion.

Putin's war economy can churn out weapons, but Russia's economy is one-tenth the size of America's. He needs to focus on rebuilding conventional forces being destroyed in Ukraine, making nuclear competition a poor investment.

China matches U.S. economic power and has unrivaled manufacturing capacity, but it would be worse off if its buildup provokes American expansion and collapses nuclear restraints entirely.

The Path Forward

Despite these common interests, negotiating new accords among three parties instead of two won't be easy. Political coalitions in each capital must simultaneously win arguments that restraint serves their national interest. The parties will need to address non-nuclear technologies that affect nuclear balances—cyber weapons and AI that are hard to count or verify.

U.S. political polarization makes Senate ratification of treaties extremely difficult, though other approaches exist: reciprocal political commitments, executive agreements, or confidence-building measures.

Trump's unpredictability could still work in favor of restraint. He might reverse course and accept some version of Putin's "strategic pause"—neither side building up while talks proceed. That would buy time to explore options before new buildups become locked in.

It would also give him a better shot at his oft-stated goal of being the president who brings home a deal to reduce nuclear weapons and their dangers.