The New START agreement between the USA and Russia is dead, and there are concerns this will lead to a nuclear-testing resurgence. Simultaneously, China spurns invitations to join a voluntary nuclear limitation treaty with the world’s largest nuclear powers.
As New START – the Treaty between the USA and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms – expired on 5 February 2026, the USA has been calling for a new nuclear-arms control treaty encompassing itself, Russia and China.
The latter has been conducting the world’s fastest-ever expansion of a nuclear arsenal. The People’s Liberation Army Rocket Force (PLARF) had an estimated nuclear-warhead stockpile “in the low 600s” by late 2024, according to a Pentagon report issued last December. Maintaining this blistering pace, the Pentagon predicted China will reach more than 1,000 warheads by 2030.
At its 3 September 2025 parade in Tiananmen Square, China proudly strutted five nuclear-weapon types: DF-61, DF-5C and DF-31BJ intercontinental ballistic missiles(ICBM); JL-1 air-launched nuclear-tipped missiles; and JL-3 submarine-launched missiles. The Pentagon estimates the PLARF has 400 ICBMs and 550 intermediate-range ballistic missiles in service. China also has three massive missile silo fields in Hami, Yumen and Yulin containing 320 silos.
The Federation of American Scientists estimates the USA and Russia have about 4,000 warheads each. Incidentally, the American arsenal has decreased in recent years, whereas Russia’s has been growing.
Notably, Washington DC accused China of secretly conducting a “yield-producing nuclear test” in 2020. This is despite Beijing claiming a moratorium on such activities and being a signatory to the Comprehensive Nuclear Test Ban Treaty (CTBT), even though it never ratified it.
Thomas DiNanno, the US Under Secretary of State for Arms Control and International Security, said at the Conference on Disarmament in Geneva on 6
February: “Today, I can reveal that the US government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons. The PLA sought to conceal testing by obfuscating the nuclear explosions, because it recognized these tests violate test ban commitments.”
DiNanno continued, “China has used decoupling – a method to decrease the effectiveness of seismic monitoring – to hide its activities from the world. China
conducted one such yield-producing nuclear test on June 22nd of 2020.”
However, the USA provided no further evidence. Oddly, nor has the USA’s annual international arms control compliance report ever listed this event. The most recent April 2025 report simply stated, “Due to the lack of transparency with regard to their respective nuclear-testing activities and previously identified adherence issues, the US remains concerned about China and Russia’s adherence to their respective moratoria.”
Nonetheless, in 2019 the State Department did raise concerns about Chinese activities at its Lop Nur test site. A 2020 report said, “China’s possible preparation to operate its Lop Nur test site year round, its use of explosive containment chambers, extensive excavation activities at Lop Nur and lack of transparency on its nuclear testing activities…raise concerns regarding its adherence to the ‘zero yield’ standard…”
The US allegation raised eyebrows. Robert Floyd, Executive Secretary of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), stated, “Regarding reports of possible nuclear tests with yields in the hundreds of tons, on 22 June 2020, the CTBTO’s International Monitoring System did not detect any event consistent with the characteristics of a nuclear-weapon test explosion at that time. Subsequent, more detailed analyses have not altered that determination.”
Dr. Jeffrey Lewis, Distinguished Scholar of Global Security at Middlebury College in the USA, highlighted DiNanno’s statement too: “It’s very carefully worded. China ‘prepared’ tests with ‘designated yields in the hundreds of tons’, including ‘one such yield-producing test on June 22, 2020’. The first wrinkle is that we don’t see such an event in China on June 22, 2020.”
Lewis noted the CTBTO International Monitoring System can detect low-yield events at Lop Nor down to a body wave magnitude of mb=3.4. He also found the
International Seismological Centre detected no events within 200km of the Chinese test site.
Explaining decoupling, Lewis said it refers to exploding a nuclear device inside a cavity, usually one created by a prior nuclear explosion. This makes the yield look 20-40 times smaller than it really is. He admitted scientists do not have too much data about decoupling, although most analysts typically use the 20-40 figure for tests conducted in rock. Using this figure, Lewis estimates the monitoring threshold for detection is a 400-900-ton explosion. “A few-hundred-ton test might go undetected, although that’s a worst-case scenario, and China probably couldn’t count on it.”
The CTBT allows sub-critical testing, where a full-fledged nuclear reaction does not occur. However, part of the problem is that it does not define what an explosion is. Possibly China interprets it to mean it can conduct small nuclear chain reactions – sometimes called hydronuclear tests – short of a full-scale detonation.
“So, what to make of all this?” Lewis mulled. “One possibility is that China is doing one-point safety tests, with overrun ranges in the hundreds of tons. That might explain the strange wording about preparing for dedicated yields repeatedly, but no events appearing.” Such one-point safety evaluations ensure the accidental detonation of a single high-explosive detonator does not cause a nuclear yield.
Lewis said safety lapses can still occur with such tests if they overrun predicted yields. In 1993, for example, a Chinese experiment resulted in contamination of
laboratory space and a subsequent move of such activities to Lop Nor. Alternatively, and more sinister, China may be testing low-yield nuclear warheads in the tens of kilotons range for new weapons such as hypersonic missiles.
Unsurprisingly, China hit back angrily at DiNanno’s accusations. Chinese Foreign Ministry spokesman Lin Jian said on 11 February that the USA’s “persistent distortion and slander of China’s nuclear policy essentially constitute political manipulation, through which the United States aims to pursue nuclear hegemony and evade its own nuclear disarmament responsibilities”.
New START had been signed in 2010, but DiNanno said “its limits on warheads and launchers are no longer relevant in 2026, when one nuclear power is expanding its arsenal at a scale and pace not seen in over half a century, and another continues to maintain and develop a vast range of nuclear systems unconstrained by New START’s terms”. He was referring to China and Russia respectively. He highlighted how China’s “buildup is opaque and unconstrained by any arms control limitations”.
US Secretary of State Marco Rubio also commented, “The president’s been clear in the past that, in order to have true arms control in the 21st century, it’s impossible to do something that doesn’t include China because of their vast and rapidly growing stockpile.”
Washington DC’s biggest problem is facing two nuclear peers simultaneously. Even then, Trump seems more intent on building defenses – such as Golden Dome – rather than expanding the US stockpile. The problem is compounded by the fact that Beijing categorically refuses to countenance joining any international arms control agreement.
Dr. Malcom Davis, Senior Analyst at the Australian Strategic Policy Institute, commented, “Here’s the hard strategic reality now emerging post-New START. With China racing to build up its nuclear arsenal and Russia now able to expand its existing nuclear arsenal, the United States must ensure it has sufficient strategic nuclear delivery systems and deployed warheads to effectively deter both China and Russia simultaneously, and deter their growing non-strategic nuclear forces, plus ensure credible, extended nuclear deterrence security guarantees to allies.”
Davis continued, “This is especially true given that Moscow and Beijing are coordinating their actions against the United States and its allies. Arms control is nice to have, but it must involve China, and it must have effective verification and monitoring provisions as part of any agreement. An effective balance of power must be restored first if future arms control is to be meaningful. Arms control cannot be an opportunity for Moscow and Beijing, working together, to gain a decisive nuclear warfighting advantage over the United States and its allies.”
On 27 November 2025, China set out its nuclear posture in a white paper entitled “China’s Arms Control, Disarmament, and Nonproliferation in the New Era”. Unfortunately, it left many questions unanswered. Indeed, the only explanation of its nuclear modernization and build-up was that it was “to safeguard China’s own strategic security and overall global strategic stability”.
However, illustrating its true nature as a political document, the white paper did a lot of finger pointing at the USA, and failed to list culprits like Russia or North Korea as concerns. For example, it said of the USA, “A certain country seeks absolute strategic superiority by constantly expanding its armaments, strengthening combat readiness and provoking bloc confrontation … In particular, this country has strengthened military alliances in the Asia-Pacific region, exercised extended deterrence and forward-deployed ground-based intermediate-range missiles, provoking tension and opposition, and severely undermining the security and interests of countries in the region.”
Although increasing dramatically, it is correct that China’s nuclear stockpile does not approach the size of Russia’s or the USA’s. “Countries possessing the largest nuclear arsenals should fulfill their special and primary responsibilities for nuclear disarmament and continue to make drastic and substantive reductions in their nuclear arsenals in a verifiable, irreversible and legally binding manner, so as to create the conditions for complete and thorough nuclear disarmament,” Beijing pleaded.
China wants others to make reduction pledges, but it refuses to engage in any voluntary restrictions itself. In fact, China warned in its white paper that it will not entertain arms control or risk reduction measures until the USA abandons its “aggressive nuclear deterrent policy based on first use,” and ceases its “hypocritical policy of inciting confrontation and creating crisis”.
As Chinese Foreign Ministry’s spokesperson Lin Jian said: “On New START, China has made clear its position on multiple occasions. We hope the US will resume dialog with Russia on strategic stability to discuss the arrangements beyond the treaty’s expiration, which is what the world would hope to see.” China is conveniently using the USA as a scapegoat, refusing to blame Russia for violating New START first, and at the same time absolving itself of the need to undertake any voluntary limitations.
Beijing paradoxically noted, “From the day it came into possession of these weapons, China has advocated their complete prohibition and thorough destruction.” It is somewhat ironic then that China is busily multiplying its nuclear stockpile rather than dismantling it.
China generously excuses itself from the treaties and limitations it feels others are obliged to follow. As the latest Pentagon report on the PLA stated, “China has not demonstrated a willingness to advance discussions on nuclear risk reduction measures, bilaterally or multilaterally among the five permanent members of the UN Security Council, except for affirming the need to maintain human control over the decision to use nuclear weapons. China unilaterally suspended a bilateral consultative mechanism with the United States on arms control and nonproliferation in April 2024.”
In light of all these developments, Lewis warned: “What I do worry about is a return to real nuclear explosions, largely because China has a lot more to gain than we do in terms of data. China has amazing supercomputers to model nuclear explosions, computers as good as the ones in the US – but what it doesn’t have is the test data. China only conducted 45 nuclear tests, most of which were atmospheric and poorly instrumented.”
Lewis explained, “If the US resumes testing, I suspect China would jump at the chance to follow suit and catch up in terms of data. Honestly, if I were the Chinese, I’d be baiting Trump to do it.”
While newer and bigger nuclear tests might occur, it is nonetheless unlikely that Russia and the USA will splurge on a nuclear-weapon arms race. Both have parity in warhead numbers, and Russia is already deeply engrossed in its invasion of Ukraine. In the meantime, China seems intent on carrying on with its secretive and unexplained nuclear buildup. (ANI)
