In early December, the nations of the world are poised to take an historic step forward on nuclear weapons. Yet most Australians still haven’t heard about what’s happening, even though Australia is an important part of this story – which is set to get even bigger in the months ahead.

On October 27 2016, I watched as countries from around the world met in New York and resolved through the United Nations’ General Assembly First Committee to negotiate a new legally binding treaty to “prohibit nuclear weapons, leading towards their total elimination”. It was carried by a majority of 123 to 38, with 16 abstentions. Australia was among the minority to vote “no”.

Given that overwhelming majority, it is almost certain that resolution will be formally ratified in early December at a full UN general assembly meeting.

After it’s ratified, international negotiating meetings will take place in March and June-July 2017. Those meetings will be open to all states, and will reflect a majority view: crucially, no government or group of governments (including UN Security Council members) will have a veto. International and civil society organisations will also have a seat at the table.

This is the best opportunity to kickstart nuclear disarmament since the end of the Cold War a quarter of a century ago. And it’s crucial that we act now, amid a growing threat of nuclear war (as we discuss in the latest edition of the World Medical Association’s journal).

But the resolution was bitterly opposed by most nuclear-armed states, including the United States and Russia. Those claiming “protection” from US nuclear weapons – members of the North Atlantic Treaty Organization (NATO), and Japan, South Korea and Australia – also opposed the ban. This is because the treaty to be negotiated will fill the legal gap that has left nuclear weapons as the only weapon of mass destruction not yet explicitly banned by international treaty.

Like the treaties that ban biological and chemical weapons, landmines and cluster munitions, a treaty banning nuclear weapons would make it clear that these weapons are unacceptable, and that their possession, threat and use cannot be justified under any circumstances.

It would codify in international law what UN Secretary-General Ban Ki-moon has said: “There are no right hands for the wrong weapons.”

Why treaties are worthwhile – even when some refuse to join

Of course, prohibiting unacceptable weapons is not the same as eliminating them entirely. So why bother?

Experience shows us that weapons treaties can make a difference – even when some countries refuse to sign, as we would expect (at least initially) with a treaty banning nuclear weapons.

For example, more than 80% of the world’s nations have signed on to the landmines ban treaty. Even though the US is not among the signatories, it has still proudly declared itself to essentially be in compliance with the landmines treaty (except in the Korean Peninsula) and plans to cease its production of cluster munitions.

Back in 1999, when the landmines ban first came into force, there were about 25 landmine casualties being reported every day around the world. According to the most recent Landmine Monitor report, those devastating landmines injuries and deaths have been reduced by 60%, to about 10 a day in 2014.

Biological weapons haven’t been used by any government since the second world war. All countries except for North Korea have stopped nuclear test explosions, even though the Comprehensive Nuclear Test-Ban Treaty has not yet entered into force because key nuclear-capable countries have not yet signed up.

And when use of chemical weapons in Syria was confirmed by a UN investigation, Russia and the US forced the Syrian regime to join the Chemical Weapons Convention. Most – though tragically not yet all – of Syria’s stockpile of chemical weapons has been destroyed.

Australia’s role in fighting a nuclear weapon ban

In voting “no”, Australia stuck out like a sore thumb among Asia-Pacific nations in at October’s UN committee meeting. All of the Association of Southeast Asian Nations (ASEAN) members – including Indonesia, Malaysia, Singapore and Thailand – as well as New Zealand and ten out of 12 Pacific island countries voted yes.

Australia is signatory to all the key international treaties banning or controlling weapons. On some, like the Chemical Weapons Convention, Australia was a leader. Australia’s active opposition and efforts to undermine moves towards a treaty banning nuclear weapons stand in stark contrast.

Australia’s stated arguments for opposing a ban treaty have varied, including that there are no “shortcuts” to disarmament; that only measures with the support of the nuclear-armed states are worthwhile; that a ban would damage the nuclear non-proliferation treaty, causing instability and deepening divisions between states with and without nuclear weapons; that it wouldn’t address North Korea’s threatening behaviour; and that it does not take account of today’s security challenges.

Perhaps the most extraordinary justification of Australia’s position came from Department of Foreign Affairs and Trade’s first assistant secretary, Richard Sadleir, who said at a Senate estimates hearing on October 20, 2016:

it is not an auspicious time to be pushing for a treaty of this sort. Indeed, in order to be able to effectively carry forward disarmament, you need to have a world in which there is not a threat of nuclear weapons and people feel safe and secure.

Can anyone seriously imagine Australian officials arguing that we need to keep stockpiles of sarin nerve gas, plague bacteria, smallpox virus, or botulism toxin for deterrence, just in case, because we live in an uncertain world?

Yet that is what Australia continues to argue about nuclear weapons. Sadleir is saying that disarmament is only possible after it has happened, when we live in an impossibly perfect world. It’s a nonsensical argument that puts off nuclear disarmament indefinitely.

As revealed in Department of Foreign Affairs and Trade internal documents, released through a Freedom of Information request, the real reason that Australia opposes a ban treaty is that it would jeopardise our reliance on US nuclear weapons.

How Australia can help with disarmament

It’s 71 years since the Hiroshima bombing, and 46 years since the nuclear non-proliferation treaty came into force, committing all governments to bring about nuclear disarmament. But that treaty is too weak: no disarmament negotiations are underway or planned.

Instead, every nuclear armed state is investing massively in keeping and modernising their nuclear arsenals for the indefinite future. The US alone has said it plans to spend about US$348 billion over the next decade on its nuclear arsenal.

Nations like Australia cannot eliminate weapons they don’t own. But they can prohibit them, by international treaty and in domestic law. And they can push other nations to do more to reduce threats to humanity – just as Australia has done with every other weapon of mass destruction.

An overwhelming majority of Australians have said in the past that they support a treaty banning nuclear weapons: 84% according to a 2014 Nielsen poll commissioned by the International Campaign to Abolish Nuclear Weapons, with only 3% opposed.

This is an issue that should be above party politics. In 2015, the Labor Party adopted a new national policy platform committing to support the negotiation of a global treaty banning nuclear weapons. At a public meeting in Perth last month, Bill Shorten said that a Labor government would support the UN resolution for a ban treaty.

In October 2016, our government let us down by voting to be counted on the wrong side of history. Thankfully, we can still expect to see the United Nations ratify the move towards a new treaty banning nuclear weapons in December, with negotiations set to begin in March 2017 in New York. It’s still not too late for Australia to change its vote, and participate constructively in the negotiations next year.