Simple yes or no.
I say yes, we should defend nearly any freedom loving allied nation from them
No.
1) Taiwan isn't recognized as a "Nation" under our policies. We recognize it as a province of China under the "One China" policy.
2) as a practical matter, China is fine with Taiwan as it is, as long as they don't get out of line. Taiwan provides investment for China, China provides cheap labor for Taiwan.
3) The issue for China is one of territorial sovereignty. Before foreigners started intervening in China, China looked like this.
After a century of interventions, drug peddling, and supporting warlords, China looked like THIS
yes, territorial integrity is a big deal for China, and not a line we want to cross.