With the expiration of the New START treaty and the erosion of arms control agreements, the safeguards that once limited nuclear danger are rapidly disappearing – despite decades of evidence that restraint reduces catastrophic risk.

A number of recent developments on the nuclear weapons radar should concern us all.

On 5 February, we saw the end of the most important nuclear weapons agreement between Washington and Moscow. The NewSTART treaty, an extension of the process initiated between George H W Bush and Mikhail Gorbachev in 1991, the  Strategic Arms Reduction treaties, significantly lowered the number of strategic offensive nuclear weapons between the two states.

The treaty was suspended some years ago amid worsening relations between Washington and Moscow but it always carried the option for renewal. That option is now gone. N ewSTART’s expiration is a further nail in the coffin of attempts to reduce nuclear dangers. It marks a new low in what has been a period of disregard for the carefully achieved arms control measures of the past.

But it is just one development showing how dangerously far the world has drifted away from restraint in nuclear policies.

Most people are unaware that the very first Resolution to be adopted by the United Nations General Assembly (UNGA) on 24 January 1946 called for the establishment of mechanisms to eliminate nuclear weapons and other weapons of mass destruction from national arsenals. Adopted by consensus and supported by the major Allied powers (the United States, the United Kingdom, France, China, and the Soviet Union), Resolution 1 recognised the hugely destructive potential that nuclear weapons held.

Yet despite us knowing of these dangers, Resolution 1 has never been implemented. There are still around 12,200 nuclear weapons in existence today – held by Russia, the US, China, France, the UK, Pakistan, India, Israel, and North Korea. The combined destructive power of this remaining global arsenal is the equivalent of 146,000 Hiroshima bombs, meaning we could drop one Hiroshima-sized bomb every day for the next 400 years, or if you prefer, one every hour for the next 17 years.

All nine nuclear weapon states are modernising their arsenals, and all threaten to use them. Analysts at the Bulletin of the Atomic Scientists’ Doomsday Clock, which measures the likelihood of catastrophic nuclear war and other planetary-destroying scenarios, last month  shifted the clock’s hands from 89 to 85 seconds to midnight – the closest we have ever been to a potential nuclear disaster. This shift is the result of continued sabre-rattling between nuclear-armed states, the dangers of misperception or miscalculation, risks of cyberwarfare and AI use, and the loss of so many treaties.

This gloomy situation wasn’t always the case: at the height of the Cold War,  America and the Soviet Union regularly engaged in talks and risk-reduction measures. But New START is now expired,  and there is no chance now for either party to renew it. The treaty ensured not only that the number of deployed strategic nuclear warheads held by each side would be capped; it also allowed for the exchange of observers, transfer of information and intentions, and the development of trust and transparency between these states. That is all gone. Other treaties, notably the Intermediate Nuclear Forces Treaty, and the Open Skies Treaty, have also fallen by the wayside.

Today, it seems that complying with international law, focusing on active diplomacy and developing international confidence-building measures, have all fallen out of fashion. But it beggars belief to think that the world is safer without the rules and constraints negotiated in the past. Such agreements were seen as hard-headed and necessary. But today there is little left to limit nuclear risks.

International humanitarian law requires that nuclear weapons will never be used. Their continued existence cannot be tolerated. The dangers of accidental or deliberate use remain too high for comfort, and the cost of maintaining them is unacceptable in a world which requires urgent attention to climate change, global inequality, genocide, and other pressing issues. The excuse that these states ‘need’ these weapons for deterrence is increasingly flimsy and risky.

The UN Treaty on the Prohibition of Nuclear Weapons (TPNW) recognises that, like other weapons of mass destruction, nuclear weapons can be stigmatised, outlawed, and eventually abolished. The technology for doing so is there; so too is the will of the people – including in Australia, where the Labor government is yet to fulfil its promise to sign the TPNW.

Eighty years ago, leaders at the UN knew that nuclear weapons posed an existential danger to humanity and the planet; this judgement remains the same today. The collapse of NewSTART and nuclear restraints more generally is no accident. It is the result of political choices and can be restored in the same way. To create a safer future, the US and Russia must act with integrity now. And our government must choose to support the elimination of nuclear weapons.