By declaring war against the German Empire, Japan, in no time after its entrance into war, captured and occupied the leased territory of Jiaozhou which Germany had gained from China in the Triple Intervention after the Sino-Japanese War, and the South Sea Islands which had been gained from Spain in the 19th century.
ドイツ帝国に宣戦布告したことにより、日清戦争後の三国干渉によってドイツが中国から得た膠州湾租借地、19世紀にスペインから得た南洋諸島を、日本は参戦後瞬く間に攻略して占領した。