What the US and the UK did here is a breach of a worldwide agreement by nuclear powers to not supply non nuclear ones in order to restrict nuclear proliferation. Which is one reason the French are pissed - the US took away their contract by breaking a rules the French had stuck to.
I don't see anything in NPT that forbids the US and UK from supplying nuclear propulsion to Australia. They are not supplying nuclear warheads.
The reason the French are pissed are strictly commercial. But that is on Naval Group. As soon as the deal was struck between Australia and Naval Group, Naval Group were changing the terms, and were years behind on some of the earliest deliveries. Had the project been going well, Australia would not have spent political capital seeking this new deal.
The French are not only 'pissed off' for commercial reasons. The deal was part of a long term strategy of France in the region, with India and Australia being the two main partners, so this has serious consequences for them beyond a simple arms sale.
Now, on the other hand, two good questions are whether the Australian ever discussed the possibility of France supplying nuclear-powered submarines instead of conventional ones, and whether France would have accepted. I don't know the answer to either though I'm doubtful about the latter and that may be an objective and very good reason for Australia to switch.
And yet it's a tacit agreement among nuclear nations to not sell military nuclear equipment to non-nuclear nations (ie who don't have at least a civilian program).
Which is why North Korea for ex has never been able to buy nuclear equipment from China or Russia. So far, because now that the US has decided breaking the rule for a short term financial gain was worth it, other's will decide that they might as well help their own allies too with a few reactors.
There is not nor has there ever been any prohibition on providing nuclear technology and equipment to non-nuclear weapons states. In this particular case, France offered to sell Australia nuclear submarines back in 2016 and Australia decided against it, but one of their reasons for going with the French proposal was that the submarines could be converted to nuclear in the future.
In 2000, the Swiss company ABB signed a contract to deliver not one, but two nuclear reactors to North Korea.
Here's the bit that should drain anyone of all faith in politicians: Donald Rumsfeld was an ABB board member at the time.
[1] https://www.swissinfo.ch/eng/rumsfeld-was-on-abb-board-durin...
https://www.ansto.gov.au/research/facilities/opal-multi-purp...
Follow the money. Christopher Pyne brokered this $50Bn deal to get re-elected (some boatbuilding would happen in SA) which blew out to $90Bn and rising.
Pyne immediately retired (got his pollie-perks-for-life golden ticket stamped) and then immediately became "employed" as a consult with the people profiting massively from this twisted deal against the public interest.
Pyne followed the same slimy playbook as Andrew Robb (4) who sneakily slipped the 99-year Darwin Port dodgy deal across the line, and then he got a free $880k "job" with them the day he left parliament shortly thereafter.
Borderline treasonous behavior is rife with our political elite (both sides stink badly)
https://www.macrobusiness.com.au/2016/04/would-you-employ-ch...
https://www.macrobusiness.com.au/2019/07/pyne-poisons-ey/
https://www.macrobusiness.com.au/2020/01/audit-office-torped...
(4) https://www.macrobusiness.com.au/2018/06/chinese-sell-andrew...
No, they're not. The sub deal with Australia was just part of a broader Pacific strategy to which Australia was central. Now that Australia sent the signal that it was to be a plugin in the US foreign policy rather than a country of its own, the entire strategy is dead and needs to be reworked. It's a major setback. It coming from the Nth sabotage of the French defense industry by the US is just the cherry on the top.
[1]: https://upload.wikimedia.org/wikipedia/commons/a/a2/Map_of_t...
https://en.wikipedia.org/wiki/Brazilian_submarine_%C3%81lvar...
Did that get an exception? Seems strange France could get that for Brazil but not Australia.
[1] https://en.wikipedia.org/wiki/Nuclear_power_by_country#Overv...
So on that note, we have nuclear technology already. Your point on proliferation does not hold.
What there has been is the NPT's Article I prohibition on the provision of nuclear weapons or nuclear explosive devices to non-weapons-states (which are all but the 5 weapons states, USA, Russia, France, UK, China). It also prohibits assistance / inducement in developing weapons.
The "(or nuclear powered)" bit has never been a thing.
There is also the Nuclear Suppliers Group, which is a group of nuclear-technology-exporting countries that agree not to export to NPT non-weapons-states a much longer list of dual-use nuclear technologies, unless IAEA comprehensive safeguards agreements are in place. Australia is a member of the NSG, and has safeguards agreements with the IAEA.
The IAEA has been informed by all three states of this new proposal.: https://www.iaea.org/newscenter/pressreleases/iaea-on-trilat...
“Fast attack” subs hunt other subs, convoys, ships, etc. they are not strategic weapons.
https://www.world-nuclear.org/information-library/nuclear-fu...
As a nation the pivot to having nuclear weapons is quite straight forward. The technology and resources are available, and the infrastructure has been researched and applied at smaller scales in the past. We're also quite invested in hypersonic projectiles, so it wouldn't take a whole lot to arm a formidable arsenal, the highest cost being political capital.
[1]: https://thebulletin.org/2021/09/the-new-australia-uk-and-us-...
What will they attack in the north?? Empty land?? Desert?? Beaches.
It would be completely pointless attacking the North. What, land in the north, then send their troops and tanks 3,000 km across a desert??
However, I doubt anyone expects an invasion of the Australian mainland. Attacks on shipping are a more likely threat. Maybe naval support to Australian allies that are closer to China.
This would be one reason why Australia might not want nuclear subs.
It is incredibly difficult to imagine a scenario where, say, China launches a naval invasion or blockade of NZ but is not already at war with our allies. In the latter case subs would engage their navy long before they reach NZ waters.
There is no reasonable expectation of an attack on Australia. This is not about defense of Australian coasts, it's about strength projection towards South China See, Taiwan Straight and Pacific Ocean.
Australia is a sovereign nation, not a client of the United States. It is free to engage in its own foreign policy and should logically want some safeguard in case its relationship with the US should ever sour.
Even if the relationship stays strong and the US makes defending Australia its top priority in a war, the US and its vast military might is on the other side of the planet - it would take many weeks to move ships to where they are needed. It is sensible for US allies to maintain forces dedicated to their own defense which are strong enough to hold out for the cavalry to arrive. A fleet of Australian nuclear subs may very well be the difference between America reinforcing a free Australia and America liberating an occupied Australia.
Any sane nation considering their own self defence and sovereignty would be looking to bolster their own position instead of relying solely on that sort of unreliable and borderline abusive relationship.
Peter Jennings, executive director of the Australian Strategic Policy Institute, backed the new deal and said his initial response was "surprise".
"The irony is that when we chose the French-designed submarine a few years ago we actually took a nuclear-powered submarine and have been spending millions of dollars turning it into a diesel submarine."The advantage of nuclear subs over diesels is the long linger time while submersed, and the range.
So I think Australia is wanting to do a little force projection of their own.
Australia spending on these subs will add to the coalition's strength, with Asia heating up rapidly.
Might also have something to do with Biden publicly demonstrating that he's going to stop the fight, consequences be damned.