Supporters of Taiwan in Taipei assert that the People’s Republic of China (PRC) has no authority to represent Taiwan. Some say the Cairo Declaration is not a treaty and lacks legal standing — in other words, it should be ignored. Others say that Japan gave up control over Taiwan and Penghu in the San Francisco Peace Treaty, but never stipulated to whom Taiwan’s sovereignty would be transferred, meaning Taiwan’s status is undetermined.
However, both arguments are outdated and should be revised based on new information.
First, the International Court of Justice (ICJ) has previously ruled that all international agreements are legally binding — this means that the Cairo Declaration has legal effect. However, the Cairo Declaration does not involve Taiwan. This was clearly explained by the declaration’s drafter, then-UK prime minister Winston Churchill, on Feb. 1, 1955. The Academia Historica’s archives about the Cairo communique also state as much.