M-pyre
The results of WW3 will determine it's destiny.
The huge military challenge for the USA is China of course.
Being nuclear powers neither nation can afford outright war as was the case with the Soviet Union and America during the Cold War.
America may not be competent in fighting land insurgencies but she does have the greatest naval power on Earth, and will for a few more decades to come.
China knows that and is desperately trying to catch up.
Also China's mishandling of the virus pandemic has severely damaged her soft power with much of the rest of the world.
For instance, China is Australia's major trading partner, indeed we are one of the few nations that have a trade surplus with China so for years a lot of Chinese apologists in Australia, just looking after the bottom line and not greater national self interest played down every transgression China has made in the South China Sea.
Not since the pandemic, the call to hold China to account is loud and clear, rationally and honestly but Australia is calling China to account for the way it allowed the virus to spread around the globe.
The problem is the USA is the West Pacific's check on China, though other nations like Japan and Taiwan and even a rising India are slowly creating alliances to add to the containment strategy, but right now the USA is seen to be so dysfunctional, even before the pandemic that confidence is shaken. For instance, Trump's betrayal of Kurds in Syria, the most noble people in that region and wildly pro American, had people around the globe relying on American power thinking "is there anyone this President will not betray? Can we really count on American power in the long term?"
Hence the scramble to find other alliances too. Not a rejection of the necessity of American power in the West Pacific, but wisely hedging bets.