If your like me, you don't know much about Taiwan. Taiwan was originally a part of China, but was later ruled by Japan. After WWII, Japan gave Taiwan it's independence.
The Republic of China was a rogue state inside of Communist China. The CCP defeated the Republic of China, so the ROC were on the run, and ended up in Taiwan.
Well, that's what I gather. Now that China has grown in strength, it feels like Taiwan should come back under the rule of mainland China.
The U.S. seeing Taiwan as a valuable asset, has decided to support Taiwan, and give military aid. This goes against the wishes of China, and here we are.
China thinks the U.S. is aiding terrorist (ROC), the U.S. sees China as the aggressor, and wants China to acknowledge Taiwan's right as a independent country.
https://en.wikipedia.org/wiki/Republic_of_China_(1912–1949)