New START Treaty Expires: The Unconstrained Era of U.S.-Russia Nuclear Arms Race

At midnight on February 5, 2026, the last legal chain hanging over U.S.-Russia strategic stability will completely break. The termination of the New START Treaty means that for the first time since the signing of the Anti-Ballistic Missile Treaty in 1972, there will be no formal binding framework between the two largest nuclear arsenals. Moscow and Washington will gain complete legal freedom to increase the number of deployed intercontinental missiles, strategic bombers, and nuclear warheads without restrictions, placing the global nuclear arms control system on the most dangerous precipice in half a century.

The immediate military situation following the treaty's invalidation.

From a technical perspective, the dramatic scene of missile silo lids opening one after another will not immediately occur at dawn on February 6. However, military preparations have long been quietly underway. Internal assessments by the U.S. Strategic Command indicate that once the treaty expires, the Pentagon could increase the number of deployed strategic nuclear warheads from the current 1,550 to approximately 2,200 within 9 to 14 months. Specific pathways include: reloading the stockpiled W87-1 warheads onto Minuteman III intercontinental ballistic missiles, restoring each missile's payload from a single warhead to a three-warhead configuration; reinstalling partially deactivated operational warheads on the Trident II D5 missiles of Ohio-class strategic nuclear submarines; and reassigning 30 B-52H strategic bombers, which had been converted for conventional missions, back to nuclear strike roles.

Russia's response capabilities are equally formidable. Sources from the National Nuclear Center located on the outskirts of Moscow revealed to Interfax last autumn that approximately 800 reserve nuclear warheads stored by Russia's Strategic Rocket Forces are on high alert. These warheads are primarily compatible with the RS-24 Yars and the new RS-28 Sarmat intercontinental ballistic missiles. More critically, several new nuclear delivery systems developed by Russia in recent years fall entirely outside the treaty framework: the Poseidon nuclear-powered torpedo with unlimited range, the Kinzhal hypersonic missile system capable of carrying nuclear warheads, and the Burevestnik nuclear-powered cruise missile currently in the testing phase. These weapons are not subject to any quantitative restrictions.

The rapid expansion of China's nuclear capabilities presents a third-party variable. The U.S. Department of Defense's 2025 Annual Report on China's Military Power assesses that China's operational nuclear warhead stockpile has exceeded 600 and is growing at a rate of approximately 80 per year. The new-generation missile silo clusters in Yumen, Gansu, and Hami, Xinjiang, are largely completed and could deploy over 200 DF-41 intercontinental ballistic missiles. Beijing has explicitly refused to join any multilateral nuclear disarmament negotiations, maintaining a consistent official stance: China will not accept any numerical limits until the United States and Russia reduce their respective nuclear arsenals to a level comparable to China's.

The Collapse Mechanism of the Strategic Stability Framework

The value of the New START Treaty extends far beyond the numerical limits on paper. The comprehensive verification and data exchange mechanisms outlined in Articles 7 to 9 of the treaty once served as crucial anchors of trust during times of crisis. In March 2023, Putin unilaterally suspended the treaty's on-site inspection obligations, citing U.S. military aid to Ukraine as undermining strategic stability. In reality, since the outbreak of the COVID-19 pandemic in 2020, the exchange of inspection teams between the two sides had largely come to a halt. The Joint Compliance and Inspection Center in Geneva has not held formal working meetings for nearly four years.

The loss of transparency has forced both sides to rely on intelligence methods for speculation. In November 2025, satellites from the National Reconnaissance Office detected unusual activity at Russia's Sevmash shipyard in Severodvinsk, suspected to be weapon loading operations for the special-purpose nuclear submarine Belgorod. Has this submarine, capable of carrying 6 Poseidon torpedoes, already been equipped with nuclear warheads? The U.S. intelligence community cannot provide a definitive answer. Similarly, Russia's Main Intelligence Directorate (GRU) is unable to confirm whether the 150 decommissioned Minuteman III missile warheads stored at Warren Air Force Base in Wyoming have been removed from their warehouses.

This information black hole has spawned a vicious cycle of worst-case assumptions. As Kingston Reif, a senior defense analyst at the RAND Corporation, pointed out in a recent seminar: When one side does not know what the other is doing, it can only plan its own actions based on the assumption that the other side is preparing for the worst. Russia might believe the United States is secretly increasing its warhead count to 2,000, and thus decide to increase its own to 2,200; upon detecting Russia's moves, the United States might then decide to further increase to 2,500. This dynamic will automatically accelerate in the absence of treaty constraints.

Historical experience provides a warning. Before the signing of the SALT I Treaty in 1972, the number of U.S. and Soviet nuclear warheads nearly doubled in five years without constraints, surging from about 8,000 to over 15,000. At that time, verification methods were limited to satellite reconnaissance, and both sides overestimated the other's actual deployed numbers by approximately 30%.

The complex impact of emerging technologies on the nuclear balance.

Hypersonic weapons and artificial intelligence are rewriting the fundamental equations of nuclear deterrence. On January 10 this year, a Zircon hypersonic missile launched by Russia from Crimea struck a target in Lviv, Ukraine, within 7 minutes, maintaining a flight speed exceeding Mach 8 throughout its journey. This speed means the warning and interception window for existing missile defense systems—including the U.S. THAAD and Patriot-3—is compressed to less than three minutes. If armed with a nuclear warhead, such weapons essentially deprive the opposing leadership of decision-making time.

The Poseidon nuclear-powered torpedo represents another form of disruption. This massive weapon, with a diameter of 2 meters and a length of 24 meters, is powered by a small nuclear reactor and can theoretically cruise at a speed of 60 knots for tens of thousands of kilometers in the depths of the ocean. Its design purpose is not to directly destroy cities, but to trigger an artificial tsunami as high as 500 meters near the coast through a megaton-level nuclear explosion, inundating the coastline with radioactive seawater. In December last year, Admiral Nikolai Yevmenov, Commander-in-Chief of the Russian Navy, told TASS that the first four Khabarovsk-class submarines capable of carrying the Poseidon will all be in service by 2027, with each submarine capable of carrying 6 torpedoes.

The intervention of artificial intelligence has introduced new risks to command and control systems. In September 2024, the U.S. Strategic Command conducted a simulation exercise in which the red team used generative AI to forge encrypted communication signals from the Russian Strategic Rocket Forces headquarters, successfully misleading the blue team into misjudging that the opposing side had entered a launch preparation state. Although the exercise included a manual intervention phase, the response time was compressed to 90 seconds. Andrey Baklitskiy, Director of the Center for Nuclear Policy Research at Moscow State University, warned that machine learning algorithms might learn nuclear escalation patterns from training data that we do not yet understand, providing recommendations in a crisis that human commanders cannot fully comprehend.

The militarization of space adds another layer of uncertainty. The Golden Dome space-based missile defense system plan promoted by the Trump administration, although still in the conceptual stage technically, has been viewed by Russia as an attempt to break the balance of mutual assured destruction. Russian Deputy Defense Minister Alexei Krivoruchko explicitly stated in October last year that if the United States deploys space-based interceptors, Russia would regard them as first-strike weapons and reserve the right to preempt.

Crisis Management Dilemmas in a Multipolar Nuclear Landscape

During the Cold War, the bilateral nuclear deterrence between the United States and the Soviet Union was relatively straightforward: both sides understood that there were no winners in a nuclear war. Today's multipolar landscape introduces complex risks of chain reactions. Suppose a conflict erupts in the Taiwan Strait, and the United States imposes nuclear deterrence on China—how would Russia respond? Would Moscow seize the opportunity while U.S. attention is diverted to take more aggressive actions in Ukraine or the Baltic region? Conversely, if Russia deploys tactical nuclear weapons in Kaliningrad, would NATO's nuclear umbrella automatically extend to Poland and Lithuania? None of these scenarios have historical precedents to follow.

The nuclear standoff between India and Pakistan serves as a regional warning. During the Kashmir crisis in February 2025, the Indian Army's Western Command once raised the alert level of the Prithvi short-range ballistic missiles to launch readiness, some of which are capable of carrying 10,000-ton-yield nuclear warheads. Simulations by the Federation of American Scientists indicate that even if India and Pakistan exchange just 50 small nuclear weapons (equivalent to the yield of the Hiroshima atomic bomb), the resulting smoke and dust would cause global temperatures to drop by 1.25 degrees Celsius within a year, disrupt the Asian monsoon system, and reduce food production by 30% the following year. Famine could claim the lives of over 2 billion people.

More concerning is the chain reaction of nuclear proliferation. If Iran ultimately crosses the nuclear threshold, Saudi Arabia has clearly stated it will seek equivalent capabilities. Japan and South Korea have long been regarded as nuclear latency states, both possessing advanced nuclear technology and sufficient plutonium reserves (Japan holds 47 tons of separated plutonium, enough to produce 6,000 nuclear warheads), enabling them to initiate weaponization programs within months. A policy draft leaked from within Japan's Liberal Democratic Party last year even included a feasibility study on the option of minimal nuclear deterrence.

The Geneva International Conference on Disarmament Negotiations has been at a complete standstill since 2023. The Russian representative refuses to discuss any new initiatives, citing the Western collective's weaponization of dialogue. The U.S. delegation insists that any new treaty must include China, while Beijing is unwilling to even accept observer status. The phased multilateral negotiation proposal put forward by the European Union has been shelved by all nuclear-armed states.

A Faint Hope on the Cliff's Edge and the Heavy Reality

Diplomatic contacts in the final week before the treaty's expiration appeared feeble. On January 28, U.S. Secretary of State Blinken and Russian Foreign Minister Lavrov held a 15-minute call, agreeing only to keep communication channels open. Kremlin spokesperson Peskov told reporters the next day: Russia's position remains unchanged; we have proposed a one-year extension of the restrictions, and now the ball is in the U.S. court. White House National Security Council Strategic Communications Coordinator John Kirby responded: The President will make a decision in due course that aligns with U.S. national security interests.

The military-industrial complex has already detected business opportunities. Northrop Grumman's stock price has risen by 18% over the past three months; the company is the prime contractor for the new-generation Sentinel intercontinental ballistic missile and the B-21 Raider strategic bomber. In Rosatom's budget application for 2026, research and development funding related to nuclear weapons has increased by 37%. The China Aerospace Science and Industry Corporation secretly established a Strategic Deterrence Systems Division last year to coordinate the integrated development of hypersonic weapons and nuclear delivery vehicles.

The voice of civil society is almost completely drowned out. Beatrice Fihn, the global coordinator of the International Campaign to Abolish Nuclear Weapons, admitted frankly at a protest held in front of the United Nations headquarters: It feels as if we have returned to the dark days before the 1962 Cuban Missile Crisis, but this time there is no secret communication channel between Kennedy and Khrushchev, no negotiating atmosphere for the Limited Nuclear Test Ban Treaty, only rising nationalism and an obsession with the display of force.

Late on the night of February 4, both the main building of the Russian Ministry of Defense on Arbat Street in Moscow and the E-wing of the Pentagon in Washington will remain brightly lit. The nuclear posture assessment teams of the two countries will conduct their final data synchronization before the agreement expires—this may be the last information exchange based on treaty obligations between the two sides for years to come. Immediately after midnight the next day, operational staff of the Strategic Rocket Forces and the Strategic Command will receive instructions that are similar in content but opposite in direction: update target lists and strike plans according to the new unconstrained environment.

Over the Atlantic and Pacific Oceans, the Cobra Ball reconnaissance aircraft and Tu-214R electronic reconnaissance planes, used for monitoring missile launches, will continue their routine patrols. However, from now on, every anomalous thermal signal and every suspicious radar waveform they collect will be fed into evaluation algorithms no longer constrained by treaty frameworks. The risk of miscalculation is quietly accumulating, much like the dust settling on the negotiation tables in Geneva, Vienna, and New York.