US won't fight directly, but will supply Japan and Vietnam and others with troops, weapons, and that kind of stuff. No difference.
Hmmm... that is somewhat possible. But if they want to defeat China for sure, then a grand alliance should be formed. All anti-China nations should become part of this alliance. I mean countries such as Japan, South Korea, Vietnam, Philippines, India (?), Taiwan, and Malaysia (?).
In addition to this, they should create a fifth column within China, comprised of the pro-Democracy individuals and organizations. These people can be used for sabotage and ambushes.
Also, Japan.etc should bribe Russia and make sure that no supply of arms and ammunition are transported to China from Russia. (This is very important, because in normal scenario, Russia will look forward to profit from the war, by selling supplies to both the sides at inflated prices).
And most importantly, all the ICBMs of China should be destroyed in sudden attacks. Else, there is a possibility of the Chinese launching at least some of its 3,000+ nukes towards Tokyo and Seoul.
I thought ICBMs were Intercontinental Ballistic Missiles, and I thought they would be launched to countries in other continents, such as NATO countries.
Russia won't be bribed that easily, after all, they still sort of support China due to their communist background and dictatorship ideas. If the anti-China countries create an alliance, it would become too noticeable, and the war must be done in a way so that the US isn't involved at all, while they are at the back plotting stuff (like Ukraine right now).
Also, I just thought of something. Russia doesn't have to stop selling Natural Gas to European countries, they can just void the contract, pay the compensation, and then propose a new contract with ridiculous prices for the Natural Gas. Europe has 2 choices: Take it or leave it. If they leave it, they'll have to find a way of generating electricity without the Natural Gas supply from Russia, with infrastructures to be built instantly. Not really possible. So they will be forced to pay ridiculous gas fees.