
Because installing our own regime gets the US cheaper access to oil(in theory) and/or allows us to shut out competition. Unfortunately, the US does not have a good track record for installing governments and those at the top dont care about innocents enough to maybe not totally cripple a country and then install a “prone to corruption” government.
China needs oil to invade Taiwan and gets it from Russia and Iran and Venezuela. The USA and China are in a techno-economic war and Taiwan has advanced tech capabilities that would greatly help China have supremacy over the USA. The vast majority of the U.S. military believes China will invade Taiwan in 2026 or soon thereafter, not the least because China has said this for years.