Today marks a pivotal moment in international arms control as the New Strategic Arms Reduction Treaty (New START), the last remaining bilateral agreement limiting the nuclear arsenals of the United States and Russia, officially expires. Signed in 2010 by then-U.S. President Barack Obama and Russian President Dmitry Medvedev, and extended once in 2021 to run through February 4, 2026, the treaty’s end ushers in an era without verifiable caps on the world’s two largest nuclear powers for the first time in over half a century. This development has sparked widespread concern among experts, diplomats, and global leaders, who warn of heightened risks of a nuclear arms race, increased global instability, and the erosion of decades of diplomatic progress.
Background on New START
New START was designed to build on previous arms control agreements, such as the original START I treaty from 1991, which helped reduce nuclear stockpiles dramatically after the Cold War. Under its terms, both the U.S. and Russia were limited to 1,550 deployed strategic nuclear warheads, 700 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers, and 800 total deployed and non-deployed launchers. Crucially, the treaty included a robust verification regime, allowing each side to conduct up to 18 on-site inspections annually, exchange data on arsenals, and monitor compliance through notifications and telemetry sharing during missile tests.
These measures provided transparency and predictability, reducing the chances of miscalculation during tense periods. Agreements like New START and its predecessors have slashed global nuclear arsenals by more than 80% since their Cold War peak, preventing an unchecked buildup that could have destabilized international security. However, geopolitical tensions, particularly Russia’s invasion of Ukraine in 2022, led to the suspension of inspections in 2023 and stalled negotiations for a successor agreement.
Russian President Vladimir Putin proposed a one-year voluntary extension of the treaty’s limits in September 2025, but the U.S. administration under President Donald Trump has not formally accepted it, with Trump stating in a January 2026 interview that “if it expires, it expires… We’ll just do a better agreement.” Despite this, recent reports indicate that the U.S. and Russia are nearing an informal deal to continue observing the treaty’s limits post-expiration, potentially averting immediate escalation. This development, negotiated on the sidelines of Ukraine talks in Abu Dhabi, could provide a temporary bridge, but it lacks the legal binding and verification mechanisms of the original treaty.
Immediate Implications for Global Security
The expiration of New START removes the last legal constraints on U.S. and Russian strategic nuclear forces, which together account for about 90% of the world’s nuclear weapons. Experts fear this could ignite a new arms race, not just between Washington and Moscow, but potentially involving China, which has been rapidly expanding its nuclear arsenal. U.S. Army Secretary Christine Wormuth expressed concerns about an “unconstrained nuclear arms race with both Russia and China at the same time.” China’s regret over the treaty’s end, coupled with its call for the U.S. to accept Russia’s extension proposal, highlights Beijing’s growing role in nuclear dynamics.
Without inspections, both sides may resort to worst-case scenario planning, assuming the other is secretly uploading additional warheads to existing missiles. This opacity increases the risk of misunderstandings, especially amid ongoing conflicts like Ukraine, where nuclear rhetoric has occasionally surfaced. UN Secretary-General António Guterres described the moment as “grave,” noting that “the risk of a nuclear weapon being used is the highest in decades.” He urged immediate negotiations for a successor framework to restore verifiable limits and reduce risks.
The treaty’s demise also undermines the broader nuclear non-proliferation regime, including the 1968 Nuclear Non-Proliferation Treaty (NPT). The NPT’s core bargain—non-nuclear states forgo weapons in exchange for disarmament progress by nuclear powers—appears increasingly hollow without active U.S.-Russia reductions. This could encourage proliferation in regions like the Middle East or Asia, where states like Iran or North Korea might accelerate their programs, perceiving nuclear weapons as essential for security.
Expert and Official Reactions
Arms control advocates have voiced alarm. The Center for Arms Control and Non-Proliferation lamented the loss of “unprecedented verification measures” and over five decades of diplomacy that averted nuclear catastrophe. Former U.S. diplomat Rose Gottemoeller emphasized that U.S. nuclear modernization is about replacing obsolete systems, not racing, but without constraints, escalation is possible.
From Russia, Kremlin spokesman Dmitry Peskov warned of a “more dangerous” world without limits, while affirming Russia’s responsible approach. Former Russian President Dmitry Medvedev echoed this, stating the expiration should “alarm everyone.” On X (formerly Twitter), users and experts highlighted the uncertainty, with one post noting the potential for quick warhead uploads and heightened instability.
European perspectives underscore regional vulnerabilities. The Stockholm International Peace Research Institute (SIPRI) called for Europe to step up in arms control, as the treaty’s end erodes NPT credibility and heightens nuclear dangers. Ukraine attributed the expiration to Russian efforts to fragment global security architecture.
In the U.S., opinions are divided. Some Republicans advocate rejecting informal extensions without guarantees, fearing unilateral U.S. disadvantages, while others urge acceptance. President Trump has expressed interest in a new deal including China, but Beijing’s arsenal remains smaller, and it has declined participation.
Pathways Forward and Broader Impacts
While the informal observance agreement offers short-term relief, experts stress the need for a comprehensive successor. The International Campaign to Abolish Nuclear Weapons (ICAN) argues that the current security environment demands urgent disarmament, not excuses for inaction. Multilateral forums like the UN could facilitate talks, but U.S.-Russia relations remain strained.
Globally, this shift could accelerate nuclear modernization programs. The U.S. has shown restraint, but without limits, pressure to expand might grow. China’s buildup, estimated to rival U.S. and Russian levels by mid-century, adds complexity. For non-nuclear states, the erosion of norms might weaken deterrence against proliferation.
In Asia, where Bangladesh and neighbors monitor great-power dynamics, the implications are profound. Increased nuclear risks could spill over into regional conflicts, affecting economic stability and humanitarian security. As Obama noted on X, expiring New START “could spark another arms race that makes the world less safe.”
Conclusion
The end of New START represents more than the lapse of a treaty; it signals a retreat from cooperative security in an increasingly multipolar world. While an informal pact may mitigate immediate dangers, the absence of binding verification heightens uncertainty. For global security, the path ahead requires renewed diplomacy to prevent a return to Cold War-style brinkmanship. As Guterres warned, this “dissolution of decades of achievement could not come at a worse time.” The world watches as the nuclear clock ticks louder
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