The collapse of the New START treaty on 5 February removes the last legally binding limits on the world’s two largest nuclear arsenals at a time of heightened global tension and nuclear threats.

With inspections halted, data exchanges frozen, and no successor agreement in place, the end of New START marks a decisive breakdown of nuclear restraint between Russia and the United States, which together possess 87% of the world’s nuclear weapons.

The treaty’s verification, notification, on-site inspection and dispute resolution mechanisms provided ongoing communication, reduced uncertainty and helped prevent miscalculation. Their loss deepens mistrust and increases the risk of escalation.

The end of New START also exposes a central failure of deterrence and arms control. Arms control can regulate numbers and deployments but does not eliminate nuclear weapons. When restraint collapses or accidents or cyberattack happen, so does the system meant to prevent nuclear catastrophe.

Dr Tilman Ruff, ICAN founding chair, said:

“New START was the last treaty constraint on the most destructive weapons ever built. Its collapse leaves the world more dangerous and less predictable. 

“We are back in a full-scale arms race. Russia and the US could double their deployed nuclear weapons within months of New START’s end unless President Trump takes up President Putin’s offer to continue to respect New START’s limits. He should do this urgently.”

“But this would not be enough. Nuclear-armed states should start negotiations to verifiably eliminate their Doomsday arsenals, as they committed to do more than 50 years ago in the nuclear Non-Proliferation Treaty.”

“The Treaty on the Prohibition of Nuclear Weapons lights the path forward. It draws a clear line—nuclear weapons are illegal, unacceptable, and must be eliminated— and it provides the only internationally agreed, verified, time-bound framework to do so.”

The end of New START has immediate implications for Australia. Close to half the US B52 bombers planned for ongoing deployment at RAAF Tindal in the NT starting this year—which were modified to be unable to carry nuclear weapons under the New START Treaty—can quickly again be made nuclear-capable. That would mean that for the first time in decades nuclear weapons could be brought into and launched from Australia, even without Australia knowing.

Dr Ruff said:

“Australia cannot credibly support nuclear restraint and disarmament while standing outside the global ban, which has been joined by over half the world’s nations. The best way to put sovereign guardrails excluding nuclear weapons around our military cooperation with the United States is to join the ban treaty. The end of New START makes doing that, as Labor’s national policy platform commits, more urgent.”

Today, the Bulletin of Atomic Scientists reset the Doomsday Clock from 89 to 85 seconds to midnight, signalling that humanity is moving closer to catastrophe.

The new setting reflects a world facing escalating nuclear dangers and a full-blown new nuclear arms race, widening wars, rapid advances in artificial intelligence, and the accelerating climate crisis. Together, these threats are compounding global instability and increasing the risk of miscalculation and mass harm.

A central driver of this worsening outlook is the collapse of nuclear restraint. The impending end of the New START Treaty will remove the last remaining, binding limits on the world’s two largest nuclear arsenals, stripping away vital guardrails against escalation at a time of heightened tension and mistrust.

The Doomsday Clock has long delivered a consistent message: tweaking nuclear weapons does not make the world safe. As long as these weapons exist, the risk of catastrophic use—by design, accident or miscalculation—remains.

 ICAN co-founder, A/Prof Tilman Ruff AO, said: 

“The Doomsday Clock is telling us what nuclear-armed states refuse to acknowledge: restraint is breaking down, and the danger is growing. They are repudiating international law and cooperation, making threats and using mis- and dis-information campaigns, and ratcheting up nuclear brinkmanship. ”

“With New START ending next week, the last limits on US and Russian nuclear arsenals are disappearing. Deployed nuclear weapons can be expected to rise alongside an arms race in space. Their failure of leadership puts everyone at risk.”

“Wars in Ukraine and Gaza, the integration of artificial intelligence into military systems, and the accelerating climate crisis all intensify instability—but nuclear weapons remain the most immediate existential threat.”

“Decades of arms control have failed to deliver disarmament. Now even those hard-won constraints are in tatters. Nuclear-armed states continue to modernise, expand and threaten to use their arsenals while forcing the rest of the world to live with the consequences.”

“The Treaty on the Prohibition of Nuclear Weapons exists because this approach has failed. It sets a clear international standard that nuclear weapons are illegal for everyone and must be eliminated, and includes the only internationally agreed framework for their elimination.”

Implications for Australia

The new Doomsday Clock setting reinforces the urgency for Australia to move beyond statements of concern and align its security policy with international law by joining the Treaty on the Prohibition of Nuclear Weapons. Dr Ruff said:

“Australia cannot credibly respond to this warning while standing outside the nuclear weapons ban, and providing increasing assistance for the possible use of US nuclear weapons, including by the deployment in Australia this year of B-52 bombers that can now carry nuclear weapons, and in future years, submarines that are likely to again carry nuclear weapons. Joining the treaty is the most meaningful step we can take to help turn the Doomsday Clock back.”

The International Campaign to Abolish Nuclear Weapons (ICAN) has warned of escalating nuclear risks after Senate Estimates confirmed the government would not stand in the way of US Virginia-class submarines entering Australian waters while armed with nuclear weapons.

The Australian Government has acknowledged it would permit visits by US Virginia-class submarines that may carry nuclear weapons in future—a direct contradiction of Foreign Minister Penny Wong’s assurance at the National Press Club in April 2023 that AUKUS submarines visiting Australia would be conventionally armed.

During Senate Estimates on Wednesday night, senior Defence officials acknowledged that there is “no impediment” under Australian policy or treaty obligations to the visit of dual-capable platforms—an aircraft, submarine or missile designed to carry either conventional weapons or nuclear weapons—and that Australia would continue to respect the US policy of neither confirming nor denying the presence of nuclear weapons.

This means Australians could unknowingly host US or UK nuclear weapons offshore—with no right to be told.

Gem Romuld, Director of ICAN Australia, said:

“The Foreign Minister’s assurance that nuclear weapons won’t be rotating through Australia is now dead in the water. It’s taken just two years for expectations of an AUKUS partner to shift, so what will come next?

If AUKUS is ‘not about nuclear weapons’, then Australia’s numerous assurances must be backed up with legal commitments. The best way to draw the line on nuclear weapons is to sign and ratify the UN Treaty on the Prohibition of Nuclear Weapons.”

The Estimates exchange centred on the United States’ nuclear-armed sea-launched cruise missile program (SLCM-N), which the US Congress has directed the Navy to develop. Experts, including CNA analyst Decker Eveleth, have publicly confirmed these weapons can be deployed on Virginia-class submarines, the same class Australia is preparing to host at HMAS Stirling as early as 2027.

National Labor policy commits the government to sign and ratify the Treaty on the Prohibition of Nuclear Weapons (TPNW). Successive Labor conferences have reaffirmed this commitment, and more than 300 federal, state and local parliamentarians have signed the ICAN parliamentary pledge.

Romuld said: 

“Australia is a strong proponent of the 1970 nuclear Non-Proliferation Treaty (NPT), an essential multilateral agreement but one that is no longer fit for purpose. The TPNW extends the work of the NPT to meet the challenges posed by today’s nuclear risks, and in finally comprehensively outlawing these weapons of mass destruction,” Romuld Said. 

“National Labor policy commits to signing and ratifying the TPNW in government, a promise yet to be delivered. It’s time for Australia to move on from just engaging with this treaty to putting pen to paper. The Prime Minister championed it and now has a responsibility to enact his policy before Australia becomes a launchpad for nuclear war.

“Both of our AUKUS partners are heavily armed with nuclear weapons. As a nation opposed to nuclear weapons, signing the TPNW puts essential protections and future-proofing in place for our country and our region.”

The International Campaign to Abolish Nuclear Weapons (ICAN), has called on the Australian government to urgently advance the signature of the Treaty on the Prohibition of Nuclear Weapons (TPNW) to address growing nuclear dangers.

The call follows last night’s ABC Four Corners investigation “Trading Fire” which highlighted elevated dangers in Australia as hosting US nuclear-capable platforms and supplying minerals that can facilitate nuclear weapons is making Australia a high probability target. 

Gem Romuld, Director of ICAN Australia, said:

“The ABC has put this issue on the national radar. The government needs to lift the veil of secrecy about what’s going on and require our nuclear-armed AUKUS partners to declare whether their vessels and aircraft are nuclear-capable or carry nuclear weapons. Australians have a right to know and a right to say no. There is no place for nuclear weapons in Australia.

To stop Australia becoming a launchpad for nuclear war we must sign the Australian-born treaty that bans the bomb and could save the world.” 

ICAN was awarded the 2017 Nobel Peace Prize for its role in achieving the TPNW. A year later, Anthony Albanese and Richard Marles led a successful resolution committing the Australian Labor Party to sign and ratify the TPNW in government. 

However when asked whether Australia would sign and ratify the TPNW on Four Corners last night, Minister Marles said;

“What’s really clear is that the [National] Conference understands that this is a decision of government… a decision of Labor in government. And the decision that Labor has made in government has been to follow the Non-Proliferation Treaty (NPT). The NPT is at the core of Labor in government’s policy.”

Dr Tilman Ruff AO, co-founder of ICAN, said:

“Minister Marles gave the impression that the Albanese Government is walking away from Labor’s longstanding ban treaty commitment. There’s no reason Australia can’t join the TPNW as well as the NPT. It can, should and must.” 

Government sources have subsequently reassured ICAN that Minister Marles’ comments do not represent a change in its policy and approach to the nuclear weapon ban treaty.

Josh Wilson, Assistant Minister for Climate Change and Energy, and Labor co-chair of the Parliamentary Friends of the Treaty on the Prohibition of Nuclear Weapon, spoke at the group’s first event of this Parliamentary term on Monday night. He said:

“The government’s position hasn’t changed. We continue to actively support disarmament and non-proliferation measures as part of our commitment to a world without nuclear weapons, and Australia recognises and values the contribution that the TPNW has made to that vital cause in terms of global focus and momentum. The Albanese government has engaged as an observer with the TPNW process, and continues to consider how the TPNW can interact with and reinforce foundation agreements like the NPT.”

Tilman Ruff said “Minister Marles is significantly out of step with his own party and platform. Hundreds of Labor parliamentarians, branches and dozens of unions back joining the treaty, as have three ALP national conferences.

As Australia pursues nuclear-fuelled submarines under AUKUS, it is essential that we send a clear message to our nation, our region and the world that nuclear weapons are a red line. We call for the government to set a timeline for the signature of the TPNW in this term of parliament.”

President Donald Trump has instructed the US Department of War to “immediately start testing US nuclear weapons” on an equal basis to China and Russia, who have recently conducted tests of nuclear-capable delivery vehicles. The last time Russia, China or the US conducted full-scale nuclear tests were in the 1990s. 

This is inconsistent with Trump’s earlier statements about the lack of value and massive cost of nuclear weapons.

“The Australian Government must make clear its opposition to the US decision and the continued nuclear brinkmanship of numerous nuclear-armed states. There are no right hands for a wrong weapon. 

It is essential that Australia fast-tracks the signature of the UN Treaty on the Prohibition of Nuclear Weapons (TPNW), to indicate we do not support nuclear weapons under any circumstances,”

said Dr Margaret Beavis, co-chair of ICAN Australia. ICAN received the 2017 Nobel Peace Prize for its work to raise awareness of the devastating humanitarian impacts of nuclear weapons, and its role in achieving the TPNW.   

“Signing the TPNW has been ALP policy since 2018. This treaty has been joined by more than half the world’s nations. Signing would reassure our region that the AUKUS submarines are not the thin end of the wedge for a nuclear-armed Australia.”  

It is also critical that Australia sends a message to our AUKUS partners that we do not accept nuclear weapons on Australian soil, and will not facilitate their use.

Despite repeated statements from both Moscow and Washington about wanting to reduce the risk of nuclear war, Putin and Trump are now restarting the nuclear arms race. 

The 1985 Reagan Gorbachev statement “a nuclear war cannot be won and must never be fought” led to vital arms control and reduced nuclear stockpiles from over 70,000 warheads to around 12,000 now. This statement was affirmed in 2022 by the P5 (China, France, Russia, the United Kingdom, and the United States) 

“The Australian government must demand disclosure about nuclear weapons on any planes and ships coming into Australia – nuclear ambiguity is not acceptable. Supporting nuclear weapons threats or use is madness, and illegal under the TPNW. Even a “small” nuclear war would be catastrophic, with a decade long nuclear winter and subsequent famine threatening the lives of billions,”

concluded Dr Beavis.