Joint exercises and cross training has been in effect for decades, the more recent AUKUS Nuclear Submarine partnership involves Australian, UK and US only, in terms of which Australia will acquire its own Nuclear subs in due course. However a lot can change before that occurs as Countries and their politicians tend to change their minds, usually for 'political' reasons, time will tell as I previously said.From what I understand this is all quiet normal with allies doing training in each other's ships, though I suppose there are more Australian, NZ, Canadian and British and other NATO Naval Officers on American ships than vice versa, simply because of there being more American ships.
