In both the 'Ying huan zhi lue' by the Qing-period Chinese writer Jiyu XI and the 'Tongsa kangmok' by the Joseon-era Korean writer Chong Bok AN, the motivation of the Wako is considered to be retribution for Goryeo-era Korea's participation in the two invasions (by the Mongols) of Japan, and as such some have argued that the actions of the early Wako, who appeared before the Oei Invasion, should be considered a local effort to recapture lost wealth and a war of vengeance against Korea and China, so these pirates should not be called Wako (Japanese pirates); according to this theory, only pirates appearing after this point should be considered 'Wako,' or Japanese pirates.
清の徐継畭の『瀛環志略』や李氏朝鮮の安鼎福の『東史綱目』には、倭寇の原因は日本に対する侵略行為(元寇)を行った高麗（朝鮮）への報復である、と記述されており、応永の外寇以前の前期倭寇は局地的な奪還・復讐戦であるとして『倭寇』と呼ばず、これ以降の後期倭寇を『倭寇』と考える説もある。