Earlier quoted context omitted.
What did the US do to prevent Russia "taking out" Crimea that the cowardly rest of the world didn't?
I am not saying it is obvious that the US would confront China militarily if it was to invade Taiwan. But Europe did let a friendly country at its immediate border get invaded and didn’t even stop buying the main resource the invader relies on (oil and gas). Let alone have any military involvement.
https://en.wikipedia.org/wiki/Budapest_Memorandum_on_Securit...