The review to determine whether the US should scrap the project is being led by Elbridge Colby, a top defence department official who previously expressed scepticism about Aukus, according to six people familiar with the matter.
Eh. Looking back, it sounds like his take is fairly nuanced. From what he's said in the past, it sounds like he's said that he doesn't think that entering the arrangement was actually worthwhile for the US, but that he's also hesitant to withdraw from an agreement once entered into.
It sounds like his argument is that the main risk of a military conflict with China over Taiwan, where these would play a role, is relatively near-term. Australia hasn't stated that it would defend Taiwan, and AUKUS won't result in an aggregate increase in submarines across the US and Australia for some time, which means that it would reduce the number of submarines available to fight China.
Assuming that all that is accurate, that seems to be a fair take to me. My guess is that what he's actually after, given his phrasing, is not trying to trying to end AUKUS, but to get Australia to also commit to defending Taiwan as a condition for it.
Speaking in London on Monday, Mr Colby said that US shipbuilding could not keep pace with the target of delivering Australia subs by 2032 and questioned why the US was giving away its most lethal assets to a country that was not even guaranteeing it would use them in the event of a conflict over Taiwan.
“If I were king for a day on the subject I would say ‘Look, you all know what my concerns are, let’s see if we can work through these together’.
I've no idea whether that's something that would be totally unacceptable to Australia or not.
At one point, the US did try to put together an analog to NATO in the Pacific, SEATO. It didn't really go anywhere. But conditions have also changed.
https://en.wikipedia.org/wiki/Southeast_Asia_Treaty_Organization
Australia was a member. Taiwan was not. But the US might be aiming to build a new Pacific alliance today.