The story goes back to 1979. It was declared by Taiwan and China that they a going to unite in one state sometime. Without declaration of future political arrangement. China those times started to conerts its a economy to market type. There was a hope in Taiwan that China will change politicaly too. But present times show that poltical system goes to authoritarian type. That is not wat democratic Taiwan wants and USA supported it.
The don't much role to part to play in the issue between china and taiwan, the problem is the agreement between china and taiwan, if taiwan trys to fight china, they will be finished.
Taiwan and China have a complex relationship, with China claiming Taiwan as a part of its territory, while Taiwan considers itself a sovereign state. Tensions arise due to cross-strait relations, military threats, and political differences.
The United States has long maintained a policy of strategic ambiguity with regards to the Taiwan issue. The US has stated that it does not support either side of the issue, and it has not taken an official stance on the issue. China has been pressuring Taiwan to accept its position that Taiwan is a part of China, but Taiwan has refused to accept this position.