The distance between New Zealand and its traditional allies has grown wider, as Australia signs a major new defence pact with the US and UK that will deliver a fleet of nuclear-powered submarines to the Pacific.

The trilateral defence partnership, dubbed AUKUS, would grant Australia access to the US’ nuclear submarine secrets and bolster co-operation in foreign policy, cybersecurity, artificial intelligence, and other emerging technologies, with the explicit intention of countering China’s rising power in the Indo-Pacific region.

Tensions between China, the US and its traditional allies have grown significantly in recent years due to concerns China’s behaviour, whether that be concerns about it ignoring international law in the South China Sea, human rights issues or trade practices. The growing rhetoric is resulting in increased militarisation and strategic positioning globally, analysts say.

Despite this, Prime Minister Jacinda Ardern said Australia’s nuclear submarines would not be permitted in New Zealand waters, in accordance with the country’s long-held anti-nuclear stance and laws, and she hinted at the Government's distaste for new nuclear-powered vessels in the Pacific.

“The centrepiece of this arrangement is the building of nuclear-powered submarines, to be based out of Australia, and Prime Minister [Scott] Morrison and indeed all partners are very well versed and understand our position on nuclear-powered vessels and also nuclear weapons.

“That of course means that they well understood our likely position on the establishment of nuclear-powered submarines and their use in the region.”

New Zealand had not been approached to join the partnership, Ardern said, “nor would I expect us to be”.

She said the pact was not “at the level” of the Five Eyes intelligence sharing treaty partnership New Zealand is part of with Australia, the US, UK, and Canada – and did not “diminish the existence of that arrangement”.

As tensions build, the Government has continued to insist it has an independent foreign policy that has it make decisions alone and outside alliances or military grouping. Ardern reiterated this on Thursday, saying the Government would take its own approach to foreign policy issues while continuing to make a contribution.

But Van Jackson, a senior lecturer in international relations at Te Herenga Waka - Victoria University, said New Zealand’s remained very interdependent with the US, Australia and the UK in different ways.

“They are autonomous and independent only in their imaginations,” he said. “You’re never going to be able to fashion good strategy if you’re not moored in reality.”

He said Australia’s strong stance against China has its own risk, and there would be risks for New Zealand because Australia is our closest neighbour, so the country would be affected by its decisions.

“It’s like New Zealand’s fate is in play, but New Zealand’s agency is not in play.”

Te Herenga Waka – Victoria University professor of strategic studies Robert Ayson said, though New Zealand was unlikely to be part of a military pact involving nuclear-powered submarines and long-range missiles, other aspects of the deal such as cyber-security would have been of interest.

“For New Zealand, there's still a concern that it's being left behind in some of these areas. But the main areas of focus for this new security partnership, those aren't areas that New Zealand expects to play in, to be perfectly blunt.” he said.

"The question is, as a New Zealander, should you be worried about that? Should you be relieved that we're not involved in that sort of stuff so much, because we are less likely to be at the pointy end of the conflict?”

Under the AUKUS pact, Australia would become only the second country the US has shared it nuclear submarine secrets with, after the UK received access in 1958.

Six countries have nuclear-powered submarines, including Russia, France, China and India.

Morrison described the pact as a “forever partnership” that was the “single greatest initiative” to secure the region since the ANZUS alliance.

“Our world is becoming more complex, especially here in our region, the Indo-Pacific. This effects us all. The future of the Indo-Pacific will impact all our futures,” Morrison said, at a joint press conference held by the three countries’ leaders on Thursday morning.

“To meet these challenges, to help deliver the security and stability our region needs, we must now take our partnership to a new level.”

Australia would not acquire nuclear weaponry or civil nuclear infrastructure, he said, and the fleet of at least eight submarines would only have conventional weapons on board.

Australia also committed to acquiring tomahawk cruise missiles, long-range anti-ship missiles, air-to-surface missiles, and to accelerating efforts to manufacture guided weapons in country.

US President Joe Biden said the pact would deepen and formalise co-operation between the AUKUS nations, “because we all recognise the imperative of ensuring peace and stability in the Indo-Pacific over the long term”.

“We need to be able to address both the current strategic environment in the region, and how may evolve. Because the future of each of our nations, and indeed the world depends on a free and open Indo-Pacific, enduring and flourishing in the decades ahead.”

The Indo-Pacific is a term use widely by US-aligned countries, and recently embraced by the New Zealand Government, to include India in the strategic picture of the Asia-Pacific region as a greater counter-weight against China’s growing influence.

Canada, also traditional national security partners of Australia, UK, and the US as past of the Five Eyes intelligence arrangement, has not been included in the new pact.

New Zealand was formerly a member of the ANZUS treaty alliance with the US, however its involvement mostly ceased in the 1980s when it refused to accept US nuclear-powered vessels in New Zealand waters.

Australia has maintained closer defence ties with the US since.

New Zealand is also not a member of the Quad, a grouping of the US, Australia, India and Japan that has becoming increasingly visible in the past few years with meetings and joint military exercises.

The Quad is also behind soft diplomacy efforts in the region including a joint response to Covid-19 and the provision of vaccines for poorer countries.

Mike Green, senior vice president for Asia and Japan chair at the Center for Strategic and International Studies, says with no equivalent to the defence grouping NATO in Asia there is a need to step up co-ordination among allies and like-minded states.

“That configuration will look a bit different for each state,” he says. “That should be easy for New Zealand – step up where comfortable is the name of the game.”