The United States and Russia could enter an unchecked nuclear arms race for the first time since the Cold War unless they secure a last-minute agreement before their final remaining arms control treaty expires in less than a week.
The New START treaty is due to lapse on February 5. Without it, there would be no restrictions on long-range nuclear arsenals for the first time since U.S. President Richard Nixon and Soviet leader Leonid Brezhnev signed historic agreements during Nixon’s 1972 visit to Moscow.
Russian President Vladimir Putin has suggested that both sides maintain existing missile and warhead limits for one more year to allow time for negotiating a follow-up agreement. U.S. President Donald Trump has yet to respond formally, stating earlier this month that “if it expires, it expires,” while emphasizing that any replacement should be superior to the current treaty.
Some U.S. lawmakers argue that Trump should reject Putin’s proposal, enabling Washington to expand its arsenal to counter China’s rapid nuclear build-up. Trump, however, has expressed a desire to pursue “denuclearization” with both Russia and China. Beijing, in turn, has deemed it unreasonable to expect participation in disarmament talks with nations whose arsenals far exceed its own.
During the height of the Cold War, the United States and the Soviet Union viewed arms limitation treaties as essential for preventing miscalculations or economically damaging arms races. Beyond setting numerical caps on missiles and warheads, these agreements also facilitate critical information-sharing, helping each side understand the other’s intentions and concerns, according to Darya Dolzikova of London’s RUSI think tank.
Without a treaty, each country would operate under worst-case assumptions about the other’s nuclear developments, said Nikolai Sokov, a former Soviet and Russian arms negotiator. “It becomes a self-sustaining process, and an unregulated arms race is inherently destabilizing,” he warned.
Since the fall of the Soviet Union, the U.S. and Russia have repeatedly updated Cold War-era agreements limiting strategic weapons aimed at each other’s cities and military bases. The most recent, New START, was signed in 2010 by U.S. President Barack Obama and Russian President Dmitry Medvedev. It caps each side at 1,550 deployed strategic warheads and 700 delivery systems, including intercontinental ballistic missiles, submarine-launched missiles, and heavy bombers.
Negotiating a replacement is far from straightforward. Russia has developed new nuclear-capable systems—the Burevestnik cruise missile, the hypersonic Oreshnik, and the Poseidon torpedo—which fall outside New START’s framework. Meanwhile, Trump has proposed a space-based “Golden Dome” missile defense system, which Moscow sees as a strategic imbalance.
China’s arsenal is also growing, unconstrained by U.S.-Russia agreements. Beijing is estimated to hold roughly 600 warheads, expected to exceed 1,000 by 2030. A bipartisan Congressional commission warned in 2023 that the U.S. faces an “existential challenge” from two nuclear powers and must prepare for simultaneous conflicts with Russia and China. Recommendations included potentially reactivating warheads removed under New START, along with restoring nuclear roles for bombers and missiles converted to conventional missions.
In U.S. policy circles, opinions are split over whether Trump should accept Putin’s one-year extension. Advocates for arms control warn that exceeding treaty limits could spark a costly and destabilizing nuclear arms race. The Congressional Budget Office estimates that modernizing and maintaining U.S. nuclear forces between 2025 and 2034 could cost nearly $1 trillion.
“Uploading additional warheads would prompt Russia to respond, and China might use it as justification to expand its arsenal,” said Democratic Senator Ed Markey. “This could trigger a new arms race that we neither need nor can win. More weapons do not make us safer.”
Conversely, some experts argue the U.S. cannot rely on Putin, noting that Russia suspended New START inspections in 2023 due to U.S. support for Ukraine. Franklin Miller of the bipartisan Congressional commission said current threats require an increase in deployed U.S. strategic warheads, though not dramatically, over several years.
When asked about Trump’s intentions, a White House official stated: “The president will decide the path forward on nuclear arms control, which he will clarify on his own timeline.” Former Russian President Medvedev, who signed New START, described Trump as unpredictable and reaffirmed that Russia is prepared to counter any new threats to its security.