As has been well publicised, Australia, the UK and the USA have signed an agreement that will make Australia the seventh country in the world to possess nuclear powered submarines. The others are the China, France, India, Russia, the UK and the USA. Unsurprisingly, the USA has the largest fleet.
Australia will build eight hunter killer submarines [SSNs] based on either the British Astute class or the US Virginia class. These will be nuclear powered but armed with conventional torpedoes and missiles, not the intercontinental ballistic missiles carried by SSBN submarines.
Eight SSNs is a substantial force. The UK has 11 nuclear powered submarines but four are SSBNs, meaning that it has only seven comparable to the Australian ones. Australia will be the only country to operates SSNs without having any SSBNs. India has only SSBNs at sea or under construction and the other five operators all have a mix of SSNs and SSBNs.
As well as the Australian boats, British SSNs may be based in Australia as part of an alliances that is clearly aimed at containing China.
The three countries involved are all part of the Five Eyes intelligence sharing network, along with Canada and New Zealand. The absence of New Zealand is unsurprising since it is a nuclear free country. For an excellent analysis of the pact in general and its impact on Canada in particular, see this post from Canadian blogger Mark Collins’s blog. The link is to part 2 but it links back to part 1.
The most controversial part of the agreement is the exclusion of France, a NATO ally that possesses nuclear submarines, has substantial interests in the Pacific and had a contract to supply Australia with 12 conventionally powered submarines, which the Australians have now torn up. France has recalled its ambassadors to Canberra and Washington, but not London, which is probably intended to suggest that the British are the junior partners in the pact.
A likely reason for the French exclusion is that President Macron stated in February 2021 that the ‘EU shouldn’t gang up on China with US.’ See this report from the Politico website.
British defence commentator Julian Lindley-French argues in his Speaking Truth Unto Power blog LINK that the French are responsible for problems with the Australian submarines contract and that their intelligence services should have got wind of the pact
Another British defence blog, The Thin Pinstriped Line, written by a former UK Ministry of Defence civil servant and Reserve officer points out that the France and the UK compete across the globe for defence contracts, which involve transfers of technology and materiel as does AUKUS. There does not appear to be anything in the treaty to commit the partners to go to war together or to joint military operations.
The most likely reason why the French were not asked to join was probably an expectation that they would have declined to do so.