There are three sets of reasons for a palpable rise in nuclear anxieties around the world: growing nuclear arsenals and expanding roles for nuclear weapons, a crumbling arms-control architecture, and irresponsible statements from the leaders of some nuclear-armed states.

One way to counter this would be for the P5 (China, France, Russia, the UK and the USthe five permanent members of the UN Security Council, which are also the five states recognised by the Nuclear Non-proliferation Treaty as lawfully possessing nuclear weapons) to co-sponsor a resolution affirming that a nuclear war cannot be won and must never be fought.

Ronald Reagan firstmadethat statement in 1984, and he and Soviet leader Mikhail Gorbachevreaffirmedit in 1987 at the signing of the historic Intermediate-Range Nuclear Forces Treaty. Today, their successors seem determined to restart a nuclear arms race and look for usable nuclear weapons.

India, Pakistan and North Korea are enlarging their nuclear arsenals as fast as they can. Chinas military hascalled fora strengthening of its nuclear-deterrence and counter-strike capabilities. Earlier this month in Beijing, the Peoples Liberation Army paraded a range of new missiles, including theDF-41heavy intercontinental ballistic missile and theDF-17hypersonic glide vehicle.

In 2017, Paul Selva, a general in the US Air Force who was then serving as vice chair of the Joint Chiefs of Staff, saidthe future of nuclear deterrencelay in small, low-yield, usable nuclear weapons. The Department of Defenses2018 nuclear posture reviewpromised two new weapons: a low-yield warhead for the Trident submarine-launched ballistic missile, and a new nuclear-armed sea-launched cruise missile.

Russian President Vladimir Putin responded in March 2018 with boasts of anew array of invincible nuclear weaponsdesigned to evade or penetrate US anti-missile defences anywhere in the world. Earlier this year heissued a warningthat Russia could place hypersonic nuclear weapons on submarines deployed near US waters and is developing the ability to trigger a radioactive tsunami in densely populated coastal areas using a new, nuclear-powered underwater drone. Russia could also deploynuclear-powered cruise missileswith unlimited range by 2025, several failed tests to date notwithstanding.

The expanded arsenals reflect the disintegrating framework of nuclear-arms control. The US withdrew from the Anti-Ballistic Missile Treaty in 2002. President Donald Trump has exited the Iran nuclear deal, killed off the INF Treaty, and rebuffed Russian overtures to extend New START. TheComprehensive Test Ban Treatyhasnt yet entered into force. Negotiations on a fissile materials cut-off treaty are yet to commence.

On 22 August, invoking the moral authority of the first city attacked with an atomic bomb, an international group of high-level experts issued the Hiroshima urgent appeal to maintain existing arms-control pacts as critical pillars of strategic stability. On 12 September, 100 Euro-Atlantic senior leaders from 24 European countriesissued a callfor a renewed commitment to arms control.

While the growing arsenals and collapsing pacts have attracted considerable media attention, the impact of the increased nuclear-tipped belligerent rhetoric is still largely below the radar. After the outbreak of the Ukraine crisis in 2014, facing hostile Western criticism of Russias backing of rebels in eastern Ukraine and its annexation of Crimea, Putin pointedly remarked: Russia is one of the most powerful nuclear nations.

In 2016, when then British prime minister Theresa May wasasked in parliamentif she would be prepared to authorise a nuclear strike that could kill 100,000 people, she answered, Yes. In 2017, Trump boasted that hisnuclear button was bigger and worked betterthan North Korean leader Kim Jong-uns. The two mocked each other withschoolyard insults and threats and counter-threats.

In February 2019, after a deadly clash between the two countries air forces, Pakistans PM Imran Khanwarned of the possibility of a nuclear war. PM Narendra Modirespondedthat Indias nukes were not reserved for celebrating the fireworks festival of Diwali. AfterIndia revoked Kashmirs autonomyin August, Khanreiteratedthat a nuclear war was a real risk. Foreign Minister Shah Mahmood Qureshirepeated the warningin Geneva on 10 September. Not to be outdone, Defence Minister Rajnath Singhtweetedthat Indias no-first-use policy could be shelved under unspecified circumstances.

The more the leaders of the nuclear-armed states revalidate the role of nuclear weapons in their national security, the more they normalise the discourse of nuclear-weapon use and embolden calls for nuclear-weapon acquisition in other countries likeGermany,Japan,South KoreaandAustralia.

Instead, the P5 should co-sponsor parallel resolutions in the UN Security Council and General Assembly to reaffirm the 1987 ReaganGorbachev declaration. This could act as the circuit-breaker amid the many threatening nuclear storms that are gathering on the horizon.

Why the UN, why both its principal organs, and why the P5?

The UN is the biggest incubator of global norms to govern the world and the vital core of the rules-based global multilateral order. The Security Council and General Assembly play complementary, reinforcing roles. The 15-member Security Council is the worlds only body with the authority to make decisions on war and peace that are legally binding and enforceable on all countries. The P5 can protect their interests with the veto. All of this makes the Security Council the geopolitical centre of gravity of the global order.

But the normative centre of gravity is the 193-member General Assembly, because the UNs unique legitimacy flows from its universal membership and its policy of one-state, one-vote formal equality in decision-making. The assemblys adoption of theTreaty on the Prohibition of Nuclear Weaponsin 2017against the united opposition of the P5was an assertion of normative primacy by two-thirds of the international community against the Security Councils geopolitical dominance.

The chief impact of the nuclear weapons ban treaty is not operational, as none of the countries that voted for it has the bomb, but normative. It dilutes the legitimacy of the continued possession of the bomb by the P5. The major motivation behind the treaty was exasperation at the failure of the P5 to pursue nuclear disarmament. They need to demonstrate nuclear responsibility rather than simply oppose the will of the majority. Otherwise, the already pessimistic mood for the 50th anniversary review conference of the Nuclear Non-Proliferation Treaty next year will deepen even more, threatening the very survivability of this critical anchor of the global nuclear order.

Co-sponsoring identical resolutions in the Security Council and the General Assembly would re-establish the P5s credentials as responsible nuclear powers without committing them to any concrete course of action.

Its biggest impact would be to harden the normative boundary between conventional and nuclear weapons that has been blurred in recent years with technological developments and serially irresponsible statements on the possession and use of nuclear weapons.

Ramesh Thakur, a former UN assistant secretary-general, is emeritus professor at the Australian National University and director of its Centre for Nuclear Non-Proliferation and Disarmament.