A World Without Nuclear Arms Control Begins This Week

The era of formal nuclear arms control between the world’s two largest nuclear powers is set to end this week as the New START treaty expires, eliminating the final legally binding limits on US and Russian deployed nuclear weapons. With prospects for renewed negotiations bleak, analysts warn the world may be entering a dangerous new phase of nuclear competition.

According to the Financial Times, the end of the agreement this week eliminates the final legally binding constraints on deployed nuclear weapons held by the United States and Russia, the world’s two largest nuclear powers, with little prospect of new negotiations to replace it.

The End of a Half-Century of Arms Control

New START was the culmination of more than five decades of efforts by Washington and Moscow to manage their nuclear rivalry. These initiatives began in the early 1970s under US president Richard Nixon and Soviet leader Leonid Brezhnev and continued through Cold War and post-Cold War agreements.

The first Strategic Arms Reduction Treaty (START I), signed in 1991 as the Soviet Union collapsed, introduced meaningful caps on strategic nuclear weapons and established verification regimes that shaped future agreements. New START, signed in 2010 and extended in 2021, limited each side to 1,550 deployed nuclear warheads, a level still sufficient to devastate much of the planet.

Ukraine War and the Collapse of Trust

Arms control discussions deteriorated sharply after Russian President Vladimir Putin ordered the full-scale invasion of Ukraine in 2022. In 2023, Moscow suspended its participation in New START and signalled it could resume nuclear testing.

US President Donald Trump later ordered the Pentagon to prepare for renewed nuclear testing “on an equal basis” with Russia and China, although it remains unclear whether this referred to explosive nuclear tests or delivery-system testing.

According to analysts, the collapse of the treaty reflects broader geopolitical hostility rather than narrow technical disagreements.

Voluntary Limits Offer Little Reassurance

Putin has suggested that both sides could voluntarily continue observing the treaty’s limits after its expiration. Trump has described the proposal as a “good idea” but has expressed preference for a new agreement that would also include China.

Former US chief negotiator Rose Gottemoeller argued that accepting a voluntary extension would be pragmatic, warning that an unconstrained arms race could disadvantage Washington. She noted that Russia has greater capacity to rapidly add warheads to existing missiles.

Verification Was the Treaty’s True Value

Experts emphasise that New START’s real strength lay not in its numerical caps but in its verification regime, which included inspections, data exchanges and thousands of notifications designed to reduce the risk of miscalculation.

These mechanisms were suspended during the Covid-19 pandemic and halted entirely after Russia’s withdrawal in 2023. Without their restoration, analysts say any extension of limits would be largely symbolic.

New Weapons Beyond Existing Agreements

The treaty does not cover several advanced Russian systems, including the Burevestnik nuclear-powered cruise missile, the Poseidon nuclear submersible, and newer hypersonic weapons. This technological evolution has further undermined the relevance of Cold War–era arms control frameworks.

Trump’s proposed “Golden Dome” missile defence initiative has drawn sharp criticism from Moscow, which argues it destabilises the balance between offensive and defensive strategic systems.

China’s Growing Role in Nuclear Calculations

While the US and Russia together control 86 per cent of the world’s nuclear weapons, China has rapidly expanded its arsenal, doubling its stockpile in recent years.

Washington has repeatedly stated that Beijing must be included in any future arms control framework. However, Chinese officials have indicated little interest in negotiations until their forces reach parity with the US.

Analysts warn that US efforts to simultaneously deter both Russia and China could become a powerful driver of a new global nuclear arms race.