New START Expires: US, Russia Without Nuclear Limits & China Factor

The last major nuclear arms control treaty between Russia and the United States, New START, expired today, February 5, 2026. Without a last-minute agreement, the two largest nuclear powers are now without contractual limits on their arsenals for the first time in decades.

New START, signed in 2010, limited each side to 1,550 deployed strategic warheads and 800 delivery systems. While neither side has excluded the possibility of a successor agreement, the path forward remains uncertain, particularly due to Washington’s insistence on including China in any future talks.

The expiration of New START marks the end of the last remaining treaty of its kind, following the demise of earlier agreements such as the ABM Treaty and the INF Treaty. The treaty covered ground-based intercontinental ballistic missiles, submarine-launched nuclear weapons, and strategic bombers. However, it did not cover shorter-range weapons or newer developments like nuclear-powered cruise missiles or underwater drones, areas the US would like to address in future negotiations.

Former US President Donald Trump reportedly showed little interest in a formal extension of New START. In January, he stated to the New York Times, “If it expires, it expires,” suggesting a willingness to pursue a “better” agreement. He has repeatedly called for China’s inclusion in any new treaty, stating he has discussed the matter with Chinese President Xi Jinping and believes Beijing might be open to participation. Trump expressed optimism that a new agreement could be reached quickly, citing his track record of “fast deals.”

Why China Rejects Negotiations

China has consistently resisted trilateral arms control negotiations. Just days ago, a Chinese Foreign Ministry spokesperson stated that it was “neither fair nor reasonable” to ask China to join nuclear disarmament talks at this time, arguing that China’s nuclear forces are not comparable to those of the US and Russia.

The US and Russia each possess over 5,000 nuclear warheads, while China is estimated to have around 600, a number that is growing at a faster pace than any other country. Experts predict China could have at least 1,000 warheads by the end of the decade. Precise figures remain difficult to ascertain.

Zhao Tong, a nuclear weapons specialist at the Carnegie Endowment for International Peace, notes that Washington is keeping its options open, including potentially increasing its own nuclear arsenal, in response to China’s build-up. Whether China intends to achieve parity in the number of warheads remains uncertain.

Massive Buildup of Nuclear Forces

China is continuing a significant expansion of its nuclear forces in both quantity and quality. During a recent military parade in Beijing, China showcased its nuclear triad – including modern hypersonic and intercontinental ballistic missiles capable of reaching both America and Europe. Chinese nuclear troops are also reportedly being maintained at a higher state of alert than previously.

Zhao Tong suggests that Xi Jinping believes China’s expansion and demonstration of greater strategic military power will help to curb what Beijing perceives as “strategic arrogance” from Washington. As long as Xi sees geopolitical benefits in a stronger nuclear force, China is likely to continue funding its nuclear build-up, aiming to compel Washington to “accept China’s rise and not challenge China’s core interests.”

Beijing’s continued refusal to provide transparency regarding its nuclear arsenal is driving reactions from the US that China then interprets as additional threats, creating a potentially dangerous cycle. This was underscored by a new white paper released by Beijing in November, its first since 2015, which stated that China “has not and will not participate in a nuclear arms race with any other country.”

The paper emphasized that China’s nuclear build-up serves to protect its strategic national interests and “global strategic stability.”

New START Has Been Crumbling for Years

Even without China’s involvement, the bilateral agreement between Moscow and Washington has been deteriorating for years. On-site inspections, a key component of New START, have not taken place since March 2020, initially due to the COVID-19 pandemic. However, in August 2022, Russia informed the US that it was suspending inspections, citing Western sanctions imposed in response to the war in Ukraine.

Russia formally suspended the treaty in 2023. President Vladimir Putin justified the decision by claiming the United States and NATO were attempting to inflict a “strategic defeat” on Russia and intrude into its nuclear facilities. Moscow stated it would continue to abide by the treaty’s quantitative limits.

Will a Nuclear Arms Race Emerge?

So far, neither side has accused the other of exceeding New START’s limits. However, this could change with the treaty’s expiration. Experts warn of a potential uncontrolled nuclear arms race, although a rapid escalation is unlikely due to technical and logistical constraints.

Kingston Reif of the Federation of American Scientists estimates the US could roughly double its number of deployed warheads in an extreme scenario. Russia could potentially increase its arsenal by approximately 800 warheads, largely through reactivating stored weapons. The Federation of American Scientists suggests similar figures. This would represent a significant reversal of decades of declining numbers.

Both nuclear powers are also modernizing their arsenals and developing new weapons systems. US observers fear a resurgence of MIRV technology – multiple independently targetable reentry vehicles – allowing a single missile to strike multiple targets simultaneously. Russia has demonstrated similar capabilities with the recent testing of the Burewestnik cruise missile and the Poseidon underwater drone.

Putin has recently returned to employing nuclear rhetoric, with reports of tests of new systems. However, these efforts did not appear to garner significant interest from Trump. Putin proposed to Trump that Russia could maintain the treaty’s limits for one year to prevent an arms race, contingent on reciprocal action from the US and a commitment not to undermine Russia’s deterrent capabilities.

Trump, however, appeared uninterested, echoing his stance from 2020 when he rejected a one-year extension, seeking instead to include China in any future agreement.

On Tuesday, Putin’s spokesperson stated that no response had been received from the Americans to Putin’s initiative and that “the world will be a more dangerous place than before” in a few days.