Of course it is in the US strategic interests, the problem is having strategic interests doesn't automatically give the US rights to intervene. Contrary to Ukraine (plain violation of the territorial integrity of a sovereign nation) the situation in Taiwan is complicated (for those who doubt it please at least make the effort to read the Wikipedia entry). Now given recent history I don't doubt the US will not let it slip when their strategic interests are at risk, but at least be lucid. Edit: To clear doubts I should add I would obviously prefer Taiwan stay an independent free democratic country. I'm only tempering the argument I sometimes see (maybe wrongly here) "it's in our best interests" = "it's the right thing".