>Everyone knows that China is not going back on a territory that is theirs by international treaties

When you said China, which China are we talking about?. the fact is, Taiwan and China is still in a Civil War.

    The United States did not explicitly state the sovereign status of Taiwan in the three US-PRC Joint Communiqués of 1972, 1979, and 1982.

    The United States "acknowledged" the "One China" position of both sides of the Taiwan Strait.

    U.S. policy has not recognized the PRC's sovereignty over Taiwan;

    U.S. policy has not recognized Taiwan as a sovereign country; and

    U.S. policy has considered Taiwan's status as unsettled.

https://en.wikipedia.org/wiki/One_China#United_States_policy