Pete Comments
The future projections in the article above for US submarines using Australia's Fleet Base West near Perth may be essentially Biden's promises that may not be pursued if he loses the November 2024 Election.
US nuclear submarines have been visiting Australia on a yearly basis for more than a decade (see this SubMattsarticle). UK SSNs visit about once every five years.
The US did have a plan decades back to use Fleet Base West as a crew changeover port BUT this plan was shelved, parhaps, in part because of cost for the USN.
The permanent US SSN Base at Guam and stopover base at Yokosuka, Japan, are closer to China's near seas than Australia's Fleet Base West. But the unique value of Fleet Base West is SSNs from it can intercept Chinese and Russian SSNs and SSBNs using the Southern Ocean route. That route is between Australia and Antarctica, between the southern Pacific and southern Indian Oceans. That route is viable in the nuclear submarine era because of nuclear submarines' rapid speed and unlimited range.