Maze was consistently praised for his impartial work at the Customs Service, but his work was made much more difficult following the Japanese occupation of Shanghai and Nanking by late 1937 as a result of the developing war between China and Japan, Chiang Kai-shek moved his seat of government to Chungking. Maze however, his administration safe within the jurisdiction of the Shanghai International Settlement, elected to remain in Shanghai but later complained that "The Chungking government (1,600 miles away) nevertheless continue to expect (at any rate on paper) the Inspector General to execute their mandates and uphold their authority in all the occupied regions, without a vestige of their protection!" Following Japanese entry into the Second World War on 8 December 1941, Maze's decision to remain in Shanghai proved a fateful one when the Japanese occupied the International Settlement that same day. As a result, Maze's duties as Inspector-General of Customs were split between operations within areas controlled by the Chinese government (C. H. B. Joly, OIG) and, until 1945, areas controlled by the Japanese and their puppet government of Wang Jingwei (Kishimoto Hirokichi, OIG 1941–1945).