Taiwan was returned to China de jure and de facto at the end of the Second World War. It became an issue only as an aftermath of the ensuing anti-popular civil war started by Kuomintang, and more especially because of intervention by foreign forces.
Taiwan question and civil war launched by Kuomintang. During the war of resistance against Japanese aggression the Chinese Communist Party and other patriotic groups pressed Kuomintang into a national united front with the Communist Party to fight Japanese imperialist aggression.