Days after North Korea fired its first ‘successful’ intercontinental ballistic missile, the world has taken a giant step towards banning nuclear weapons – except Australia.

Nations gathered at the United Nations in New York last week to finalise a nuclear ban treaty, described by one expert as the “most significant development in multilateral nuclear arms control” in two decades.

More than 120 countries approved the treaty on Saturday morning (AEST). But Australia, unconvinced by the entire process, was not even in the room.

The move has infuriated disarmament advocates, who have labelled it a “boycott”.

“I think not taking part is petulant and counter-productive,” said Professor Ramesh Thakur, Director of the Centre for Nuclear Non-Proliferation and Disarmament at the Australian National University.

Professor Thakur told The New Daily it was understandable if Australia eventually chose not to sign the treaty immediately, noting that the drafts had appeared “incompatible with our alliance policy and the nature of the relationship with the US”.

“But not taking part in the conference is scandalous. It’s disgraceful.”

The treaty, once formally ratified by member nations, will prohibit the use or threat of use of nuclear weapons and outlaw their possession.

Conference President and Costa Rica’s ambassador to the UN in Geneva, Elayne Whyte Gomez, hailed the “historic” vote.

In March, the US, alongside nations such as Australia, France and Britain, also skipped earlier treaty talks, a crucial precursor to this week’s conference.

“Is there anyone that believes that North Korea would agree to a ban on nuclear weapons,” US ambassador Nikki Haley said at the time.

The Australian government, meanwhile, has argued such a treaty “does not offer a practical path to effective disarmament or enhanced security”.

It also says that such an agreement could undermine the Nuclear Non-Proliferation Treaty (NPT), which seeks to prevent the spread of nuclear weapons beyond the five original weapons powers – the US, Russia, Britain, France and China.

But not everyone is convinced.

“I think that’s an absurd position, frankly,” John Carlson, former director general of the Australian Safeguards and Non-Proliferation Office, told The New Daily. “It’s just an unsubstantiated assertion.”

Professor Thakur agreed, noting that “under the NPT, not a single warhead has been eliminated in 49 years”.

DFAT says Australia “rightly regards as the cornerstone of the global non-proliferation and disarmament architecture”.

Yet according to Mr Carlson, now a non-resident fellow at the Lowy Institute, the boycott was more to do with the US alliance than the NPT.

“The present government wants to be close to the United States and regards it as essential to our security,” he told The New Daily.

“It’s not prepared to take issue with the United States on the issue of nuclear weapons. That’s unfortunate.

“What we should be is a voice of alternative opinions to the United States and our other allies. What we seem to be doing at the moment is sitting on our hands doing nothing.”

Greens Senator Scott Ludlam, who flew to New York to observe the talks, said the alliance with the US was “no excuse” and pointed to the participation of New Zealand, an ANZUS signatory.

“I think it’s sheer gutlessness,” he told The New Daily.

Senator Ludlam said the NPT had become a “forum for sandbagging and delay” and that last week’s conference was a sign “the rest of the world has finally had enough”.

“What we have here, instead of perpetual delay, is action. It’s an enormous shame that Australia boycotted these negotiations.”

A DFAT spokesperson told The New Daily the government had been “closely monitoring” events at the conference.

Aside from the Netherlands, all other NATO countries have skipped the talks. Japan, a nuclear umbrella state and the only nation to have been hit by a nuclear attack, was also absent, as were all nuclear-armed nations.

Compared to the failings of the NPT, Professor Thakur was optimistic: “We’ve had proven success in one month, versus proven demonstrable failure in 49 years.”