I think you can make a strong case US hegemony may be in decline, but it’s harder to claim it’s gone
Why do you assume it was/will be replaced?
It could go back to the laissez-faire system that was present when all the European powers were running around basically doing anything they wanted. (It should be noted that the US wasn't as isolationist as the propaganda would have you believe: how else did they get pre-revolution Cuba, PR, Guam, Hawaii, etc.?)
I don’t think the US has been isolationist since before the Spanish American war.
I agree that US hegemony isn't gone yet, but we've lost so much of our manufacturing and materials sourcing that we'll soon need them more than they need us.
Having a nice battleship group does little for the average american public.
"Every gun that is made, every warship launched, every rocket fired signifies, in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed. This world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children. The cost of one modern heavy bomber is this: a modern brick school in more than 30 cities. It is two electric power plants, each serving a town of 60,000 population. It is two fine, fully equipped hospitals. It is some fifty miles of concrete pavement. We pay for a single fighter with a half-million bushels of wheat. We pay for a single destroyer with new homes that could have housed more than 8,000 people. . . . This is not a way of life at all, in any true sense. Under the cloud of threatening war, it is humanity hanging from a cross of iron." Eisenhower
That same adversary wouldn't sink a second [15 carriers in the next hour . . . 'cos they'll all be sunk]
> Back in reality, it's true [China] could ... sink 15 aircraft carriers [in an hour].
That is unlikely. The Chinese military relies on a combination of overwhelming manpower and tactical positioning, not aircraft superiority and tactical missile deployment (although they are equipping with more and more ballistic missiles). This puts the US at a distinct advantage in almost every conflict with the Chinese military. This includes the South Seas.
The presence of the 5 US carriers* off Singapore has deterred the staged Chinese invasion force for the last few months
https://www.stripes.com/news/pacific/china-sends-two-aircraf... - 3 carriers sent.
2 More were sent by Trump in September (https://www.youtube.com/watch?v=mvgKgLVPckA). .
[1] https://en.wikipedia.org/wiki/List_of_submarine_classes_in_s...