the islands as having "low cultural, economic and political development". The terms of the Mandate specified that the islands should be demilitarised and Japan should not extend its influence further into the Pacific. The Mandate was initially subject to yearly scrutiny by the Permanent Mandates Commission of the League of Nations in Geneva, though by the late 1920s Tokyo was rejecting requests for official visitation or international inspection. In 1933 Japan gave notice of withdrawal from the League of Nations, the withdrawal becoming effective two years later. Administration Following the initial Japanese occupation of the islands, a policy of secrecy was adopted. Japan made it plain that it did not welcome the entry of foreign ships into Micronesian waters, even those of its wartime allies. During the first five years that Japan occupied the islands, it consolidated its presence and the islands became a virtual Japanese colony. The IJN divided the territory into five naval districts in Palau, Saipan, Truk, Ponape and Jaluit Atoll, all reporting to a rear admiral at the naval headquarters at Truk. A proposal at the Versailles Conference to allow trade and migration between those islands to be administered by Japan and those to be administered by Australia and New Zealand was rejected. Japan was able to continue administering the islands as if they were colonial possessions, keeping their waters off-limits to foreigners. When the islands became legally a League of Nations Mandate, their Class C status gave Japan direct control over their domestic legal system. Japan administered them as Japanese territory and as part of the Japanese Empire. This situation continued even after Japan withdrew from the League of Nations in 1935 and lost its legal claim to administer the islands. Militarily and economically, Saipan, in the Marianas archipelago, was the most important island in the South Seas Mandate and became the center of subsequent Japanese settlement. The towns of Garapan (on Saipan), Koror (on Palau) and Colony (on Ponape) were developed to resemble small towns in Japan, with cinemas, restaurants, beauty parlours and geisha houses. Another important island was Truk in the Carolines archipelago, which was fortified into a major navy base by the IJN. Between 1914 and 1920 the islands began the slow transition from naval to civilian administration. By 1920 all authority had been transferred from the Naval Defense Force to the Civil Affairs Bureau which was directly responsible to the Navy