The US has defense commitments in the Pacific to all of the Central and Western Pacific nations with the exception of the Southwest Pacific states more closely aligned with Australia, all the way to Japan, South Korea, Taiwan, and Australia. Practically all of the Pacific, much less NATO, and pretty much all of Latin America.
Does Australia have the same defense commitments? And while its not on paper, with the large number of Jews in the US northeast corridor, we have commitments to Israel as well.
US defence commitments area all well and good. Given this is a RAN thread, one should look at what Australia's defence commitments are, and what the ADF has to meet them with, as well as the resources that Australia can draw upon.
IIRC the regular establishment of the ADF as a whole is similar to of the USCG. The ADF has ~50,000 - 53,000 personnel, while the USCG has ~41,500 and there are ~1,260,000 regulars in service in the US across the US Army, USAF, USN, USMC and USCG.
Also while Australia has comparable land and sea claims to that of the US, the US has a population of ~300 mil. while Australia has a population of only ~22 mil. or roughly the population of the State of Texas, less the population of the State of Connecticut or Iowa.
Something else to consider. Australia has EEZ claims around Heard Island, and Perth WA being the closest major population centre is over 4,100 km away. Of the major population centres on the East Coast where most Australians live, Melbourne VIC is closest, at ~5,600 km.
Now, how about instead of attempting to engage in a hypothetical 'size-measuring' contest, we instead discuss what is relevant, reasonable and appropriate for Australia's naval capabilities and requirements as that is what this thread topic is supposed to be about, hmm?