Aukus: Could Trump sink Australia's submarine plans?

Australia's defence minister woke up to a nightmare earlier this week - and it's one that has been looming ever since the United States re-elected Donald Trump as president in November.

A landmark trilateral agreement between the US, UK and Australia - which would give the latter cutting-edge nuclear submarine technology in exchange for more help policing China in the Asia-Pacific - was under review.

The White House said on Thursday it wanted to make sure the so-called Aukus pact was "aligned with the president's America First agenda".

It's the latest move from Washington that challenges its long-standing friendship with Canberra, sparking fears Down Under that, as conflict heats up around the globe, Australia may be left standing without its greatest ally.

"I don't think any Australian should feel that our ally is fully committed to our security at this moment," says Sam Roggeveen, who leads the security programme at Australia's Lowy Institute think tank.

On paper, Australia is the clear beneficiary of the Aukus agreement, worth £176bn ($239bn; A$368bn).

The technology underpinning the pact belongs to the US, and the UK already has it, along with their own nuclear-powered subs. But those that are being tly designed and built by the three countries will be an improvement.

For Australia, this represents a pivotal military capabilities. The new submarine model will be able to operate further and faster than the country's existing diesel-engine fleet, and allow it to carry out long-range strikes against enemies for the first time.

It is a big deal for the US to share what has been described as the "crown jewel" of its defence technology, and no small thing for the UK to hand over engine blueprints either.

But arming Australia has historically been viewed by Washington and Downing Street as essential to preserving peace in the Asia-Pacific region, which is far from their own.

It's about putting their technology and hardware in the right place, experts say.

But when the Aukus agreement was signed in 2021, all three countries had very different leaders - Joe Biden in the US, Boris Johnson in the UK and Scott Morrison in Australia.

Today, when viewed through the increasingly isolationist lens Trump is using to examine his country's global ties, some argue the US has far less to gain from the pact.

Under Secretary of Defence Policy Elbridge Colby, a previous critic of Aukus, will lead the White House review into the agreement, with a Pentagon official telling the BBC the process was to ensure it meets "common sense, America First criteria".

Two of the criteria they cite are telling. One is a demand that allies "step up fully to do their part for collective defence". The other is a purported need to ensure that the US arms industry is adequately meeting the country's own needs first.

The Trump istration has consistently expressed frustration at allies, including Australia, who they believe aren't pulling their weight with defence spending.

They also say America is struggling to produce enough nuclear-powered submarines for its own forces.

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