>The US cannot fight two wars vs Russia and China.
US is winning conventional war with Russia without losing a single soldier and using 1-2% of what they spend on Iraq war.
>China will use this opportunity to take back Taiwan.
Sure, "take back". Use factual words - invade.
>China knows that if they let Russia be defeated, then they are next.
Next of what? Being defeated when they rush into extremely aggressive, genocidal war? They need to be sure of that, yes. Russia's loss is 100% self inflicted.
The US plan is to first defeat Russia, and then to defeat China. They expect China to wait their turn. However the US will not win this war. If Russia's existence is at stake, they will use their nuclear weapons. There is very little chance that this war will remain conventional.