Remember that the defender has home team advantage. That’s precisely what you see happening both in Iran and Ukraine. That advantage exists with Taiwan. There’s a reason that China hasn’t made a move in all these years, and the US is only one part of that equation.

Homefield advantage is relative, between Ukraine - Iran - Gaza, Taiwan is closer to Gaza, which is to say not much after mitigating outside spoilers. Maybe less than Gaza vs force disparity involved. US is/was one part of equation, but big part of equation.