Instead of absolute dollar amounts, if you compare China's military purchasing power with the US, adjusting for different labor costs and the fact that they don't include things like R&D in their military budget, then China is much closer to US spending than it appears.
Having a supply line to Asia versus China fighting close to home, that is a recipe for disaster.
It's not even a secret at all to at least millions of folks across the world. It's only the strange American media and brainwashing system that presents the idea that China can be threatened with force.
In that sense it's highly dubious Beijing is directly involved with Myanmar's current regime change. They can achieve their objectives anyways without getting their hands dirty. Of course there may be intermediaries involved that straddle both camps so it's not clear cut either.
[1] https://www.csis.org/programs/technology-policy-program/surv...
It's worth remembering that World War II was a conflict where one side was fighting on a supply line 4,000 miles long, 3,000 by sea, and the other side was fighting a hundred miles past its own borders. The supply problems in the conflict were mostly concentrated in the latter country.
I can't speak to the quality of the Chinese military, but the US military is regarded as having perhaps the single most effective military logistics in world history.
If you know anything about logistics you'd conclude that the latter had a much harder logistical challenge, especially since the Axis didn't have much of an Atlantic Navy.
The issue of a US v China confrontation is that this won't repeat. The US will not be able to go unopposed in the seas, and it will have to supply with non-naval means.
Also, it's worth remembering that in the case you're talking about, the US against the Axis in Europe, the US was not a major or deciding force, which is a major part of why it was able to afford such extended supply lines. In an alternative scenario where the rest of the Allies were so weak as that the US was the dominant power in the conflict, maintaining those supply lines would have been incredibly difficult.
> "The Other Side" was fighting on four fronts at their borders, and had supply lines a thousand miles long on ground
Do remember that it's basically fighting the same enemy on all the fronts (who have the same this-is-not-close issue as Germany). In the one case where it's different, keep in mind that Soviet factories were moved east of the Urals to places like Novosibirsk, which is further from Moscow than Berlin is to Moscow.
> the US against the Axis in Europe, the US was not a major or deciding force
The US was about ½-⅔ the total force in Western Front. While the Western Front was smaller than the Eastern Front, the US also played a major role in the supply chain of the USSR--virtually all of the trucks and trains that kept the USSR's war economy running were supplied by the US, which was also supplying Chang Kai-Shek via The Hump (although Britain was responsible for those logistics), while meanwhile reconquering the Philippines and other Pacific islands from the Japanese. And don't forget, most of the US manufacturing is several hundred miles from the coasts (the Great Lakes don't count for transoceanic shipping purposes).