SG Talk

[size=11] compared to Taiw[/size]
Ukraine is about 17 times bigger than Taiwan. ... Taiwan is approximately 35,980 sq km, while Ukraine is approximately 603,550 sq km,
.......

How long can  usa defend taiwan is a question without involving in it directly.  It is a big question.

It's up to China not US on Taiwan. 
Just block, US warship cannot enter. 
Not like Ukraine, it borders Poland. 
So there is an escape route. 
Taiwan once surrounded , it's over.