Thursday Marks the End of Nuclear Arms Control as We Know It

In 48 hours, the last meaningful constraint on the world's two largest nuclear arsenals will simply vanish.

New START, the final survivor of six decades of nuclear arms control agreements, expires this Thursday. Donald Trump—who once called nuclear weapons the "biggest problem" in the world—has decided to let it die. His reasoning? "If it expires, it expires."

With that casual dismissal, the United States and Russia will be free to begin building nuclear weapons without limits for the first time since the 1960s. It's a competition both nations have successfully avoided for decades, and one that even Moscow doesn't want.

The Last Treaty Standing

New START, in force since 2011, caps American and Russian strategic nuclear weapons at 1,550 warheads each. These are the long-range missiles and bombers capable of crossing continents—the weapons that could end civilization as we know it.

The treaty represents the culmination of a remarkable journey. In the 1980s, the superpowers aimed roughly 20,000 strategic warheads at each other. Today, thanks to successive agreements starting with Richard Nixon's SALT talks, that number has dropped by more than 90%.

Even Russia wants to keep the treaty alive. Despite suspending information exchanges in 2023 over Ukraine, Moscow offered to observe the numerical limits for another year. The Trump administration has shown zero interest. As nuclear researcher Pavel Podvig noted, "the US expert and political community has essentially reached consensus on the need to expand the US strategic arsenal."

The Shakedown That Saved Arms Control

New START's path to ratification reveals how nuclear politics really work. When Barack Obama presented the treaty to the Senate in 2010, GOP hawks blocked it until Obama agreed to spend tens of billions on nuclear modernization programs. It was essentially a shakedown—the nuclear weapons industry demanding payment in exchange for arms control.

But the deal worked. New START included stronger verification procedures and simplified counting rules that made compliance easier. A bomber that could carry multiple warheads counted as just one weapon, because the total number mattered more than the delivery method.

If you'd told Cold War experts in 1985 that Soviet and American arsenals would one day be limited to 1,550 warheads each, they would have laughed. Yet here we are—or were, until Thursday.

Trump's China Gambit

Trump now claims he wants a "better" treaty that includes Chinese nuclear forces. China has already rejected the idea, but that's likely the point. Demanding Chinese participation is almost certainly a poison pill designed to kill any progress on extending the existing treaty.

Bilateral arms agreements are difficult enough. Multilateral ones are exponentially harder. Trump knows this, which suggests his real goal isn't a better treaty—it's no treaty at all.

The president is surrounded by advisers who view arms control agreements as signs of weakness and treaties as annoying limitations on American power. The Navy Secretary even wants to put nuclear weapons on Trump's proposed new battleships, reviving a dangerous Cold War practice that George H.W. Bush abandoned over 30 years ago.

Beyond the Numbers Game

What happens next depends, as so much does in this White House, on whatever strikes Trump as a good idea. The least destructive option would be to simply leave things alone for now. Both sides could continue observing the limits without a formal treaty.

But arms control is about more than numerical limits. Regular meetings, inspections, and information exchanges build trust and relationships that prove crucial during crises. The 1973 Yom Kippur War, for example, ended with the US putting nuclear forces on alert—just one year after signing the SALT Treaty. The personal relationships built through arms control helped prevent that crisis from escalating.

A more likely outcome is that Trump will authorize more money for more nuclear weapons. Such expansion would be pointless from a security perspective. America already possesses enough firepower to destroy both Russian and Chinese governments with a relative handful of weapons. More bombs won't create more security.

The Real Stakes

As Emma Belcher from the arms control organization Ploughshares told me, failing to replace New START would "contribute to greater geopolitical instability, escalated tensions across the world and a higher likelihood of a nuclear catastrophe in our lifetime."

Deterrence isn't just about technology and numbers—it's about will, commitment, alliance strength, and above all, the shared fear of nuclear catastrophe. The Cold War taught us that much.

Trump once said, "I think, to me, nuclear is just the power. The devastation is very important to me." If the president truly cares about what he called the world's biggest problem, he has until Thursday to do something about it.