What Australia lacks in facing China's massively larger conventional forces AND China's nuclear capability is nuclear armed allies besides the US. Under Trump the US taking its dependent allies for granted was convincingly displayed. After 4 years of Biden Trump could well return in 2024-25. Or perhaps some other US Presidential isolationist, even more alliance-threatening than Trump, could darken international relations.
In part consideration of this Australia has made its two largest naval purchases (France's Attack-class subs and UK Hunter class frigates) as long term alliance sweeteners with (non-US) nuclear allies.
The France Navy has long sailed its ships into Australia's region (for more than 250 years) and less obviously its subs (since WWII). The medium-long term threat from China is not only to Australia. France sees China as a strategic and neo-colonial threat to France's Indian and Pacific Ocean interests. Hence France has perhaps raised the intensity of its ship and sub flotilla visits.
Australia in part chose the French Naval Group (Attack class) submarines to increase the chances French naval vessels, especially those with a nuclear content like the SSN Émeraude, would visit Australia's region. Within this region the most contested and critical strategic and trade zone is the South China Sea.
The French Government, which owns Naval Group has its own Indian and Pacific Ocean French overseas island territories, SLOCs and great power status reasons to sail the waters in Australia's region. BUT A$100+ Billions to France over the 60 year life of the Naval Group Attack class Program is also a compelling bilateral economic argument for a closer bilateral strategic alliance with Australia.
An even more impressive symbol of French naval power allying with Australia's (and broader de facto China Containment Quadrilateral) strategic interests is the visit of the French Mistral-class LHD Tonnerre. The La Fayette-class stealth frigate Surcouf is escorting Tonnerre for training "MISSION JEANNE D'ARC 2021" bilateral and multilateral naval exercises. The Tonnerre led flotilla has been active since early 2021 and will end when Tonnerre and Surcouf return to the French home naval base of Toulon on July 14, 2021 (appropriately Bastille Day).