Some Koreans advance the claim that Tsushima was a vassal state of Korea during the Joseon dynasty and should therefore be under South Korea's territorial control; proponents of this view cite 'the military expedition to suppress the Wako' that was sent against Tsushima during the Oei Invasion as proof of this.
韓国人の間では、対馬は朝鮮王朝の属国であり、韓国に領有権があるとの主張がなされることがあるが、その根拠の一つに、応永の外寇における対馬への『倭寇討伐』が上げられている。