South Seas Mandate
The South Seas Mandate, officially the Mandate for the German Possessions in the Pacific Ocean Lying North of the Equator, was a League of Nations mandate in the "South Seas" given to the Empire of Japan by the League of Nations following World War I. The mandate consisted of islands in the north Pacific Ocean that had been part of German New Guinea within the German colonial empire until they were occupied by Japan during World War I. Japan governed the islands under the mandate as part of the Japanese colonial empire until World War II, when the United States captured the islands. The islands then became the United Nations-established Trust Territory of the Pacific Islands governed by the United States. The islands are now part of Palau, the Northern Mariana Islands, the Federated States of Micronesia, and the Republic of the Marshall Islands.
In Japan, the territory is known as "Japanese Mandate for the Governance of the South Seas Islands" and was governed by the Nan'yō Government.
Origin
Japanese interest in what it called the "South Seas" began in the 19th century, prior to its imperial expansion into Korea and China. By 1875, ships from the newly established Imperial Japanese Navy began to hold training missions in the area. Shiga Shigetaka, a writer who accompanied a Navy cruise to the region in 1886, published his Current State of Affairs in the South Seas in 1887, marking the first time a Japanese civilian published a firsthand account of Micronesia. Three years later, Shiga advocated for annexation of the area by claiming that doing so would "excite an expeditionary spirit in the demoralized Japanese race." Despite the appeal imperialism had for the Japanese public at the time, neither the Meiji government nor the Navy seized any pretexts to fulfill this popular aspiration. It was through the commercial operations of fisherman and traders that the Japanese first began to make a wider presence in the region, which continued to grow despite challenges from competing German commercial interests. Although the Japanese public's enthusiasm for southward expansion had abated by the turn of the century, a number of important intellectuals, businessmen, and military officials continued to advocate for it. Among them were Admiral Satō Tetsutarō and Diet member Takekoshi Yosaburō. The latter declared that the future of Japan "lies not in the north, but in the south, not on the continent, but on the ocean" and that its "great task" was to "turn the Pacific into a Japanese lake."By the outbreak of World War I the empire included Taiwan, Korea, the Ryukyu Islands, the southern half of Sakhalin island, the Kuril Islands, and Port Arthur. The policy of Nanshin-ron, popular with the IJN, held that Southeast Asia and the Pacific Islands were the area of greatest potential value to the Japanese Empire for economic and territorial expansion.
The Anglo-Japanese Alliance of 1902 had been signed primarily to serve Britain's and Japan's common interest of opposing Russian expansion. Amongst other provisions the treaty called on each party to support the other in a war against more than one power, although it did not require a signatory state to go to war to aid the other. Within hours of Britain's declaration of war on Germany in 1914, Japan invoked the treaty and offered to declare war on the German Empire if it could take German territories in China and the South Pacific. The British government officially asked Japan for assistance in destroying the raiders from the Imperial German Navy in and around Chinese waters, and Japan sent Germany an ultimatum demanding that it vacate China and the Marshall, Marianas and Caroline Islands. The ultimatum went unanswered and Japan formally declared war on Germany on 23 August 1914.
Japan participated in a joint operation with British forces in autumn 1914 in the Siege of Tsingtao to capture the Kiautschou Bay Leased Territory in China's Shandong Province. The Japanese Navy was tasked with pursuing and destroying the German East Asia Squadron and protection of the shipping lanes for Allied commerce in the Pacific and Indian Oceans. During the course of this operation, the Japanese Navy seized the German possessions in the Marianas, Carolines, Marshall Islands and Palau groups by October 1914.
After the end of World War I, the protectorate of German New Guinea was divided amongst the war's victors by the Treaty of Versailles. The southern part of the protectorate was mandated to come under Australian administration as the Territory of New Guinea, consisting of Kaiser-Wilhelmsland and the German-controlled islands south of the equator. Meanwhile, Japanese occupation of the northern part of the protectorate, consisting of the Micronesian islands north of the equator, was formally recognized by the treaty. Japan was given a League of Nations Class C mandate to govern them, the C Class being assigned because the Mandates Commission regarded the islands as having "low cultural, economic and political development". The terms of the Mandate specified that the islands should be demilitarized 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. As there was no legal requirement for Japan to be a League member for it to have a mandate over the islands, it continued to administer them and submitted annual reports to the League until the outbreak of World War II. The idea of reassigning the mandate was considered by the League and the great powers but proved to be impractical.
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, even those of its wartime allies, into Micronesian waters. 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, Koror and Colony were developed to resemble small towns in Japan, with cinemas, restaurants, beauty parlors and geisha houses. Another important island was Truk in the Carolines archipelago, which was fortified into a major navy base by the IJN.
File:Police officer at Chuuk, Micronesia in 1931.png|thumb|upright|left|Native Micronesian teaching assistant and constables of Japanese Truk Island, c. 1930. Truk became a possession of the Empire of Japan under a mandate from the League of Nations following Germany's defeat in World War I.
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 Ministry. Initially based in Truk, the Civil Affairs Bureau was moved to Koror in the Palau islands in 1921. The naval garrisons were disbanded to comply with the terms of the Mandate. In April 1922 a civilian government was established in each of the six administrative districts in the form of a civil administration department which still reported to the local naval garrison commander. At the same time a post of Governor of the South Seas Mandate was created. Governors were mostly admirals or vice-admirals as the administration was initially still the responsibility of the IJN. The Governor reported directly to the Prime Minister of Japan. After the establishment of the Ministry of Colonial Affairs in June 1929, the Governor reported to the Minister of Colonial Affairs instead. The establishment of the "South Seas Government" or "Nan'yō-chō" in March 1932 finally put the government of the islands under a purely civilian administration. When the Ministry of Colonial Affairs was absorbed into the Ministry of Greater East Asia in November 1942, the primacy of the IJN was again recognized by the appointment of an admiral as the Governor. Furthermore, the six administrative districts were reduced to three in November 1943: North, East, and West.
Significance
The population of the South Seas Mandate was too small to provide significant markets and the indigenous people had very limited financial resources for the purchase of imported goods. The major significance of the territory to the Empire of Japan was its strategic location, which dominated sea lanes across the Pacific Ocean and provided convenient provisioning locations for sailing vessels in need of water, fresh fruit, vegetables and meat.As a signatory of the 1922 Washington Naval Treaty, Japan agreed not to build new naval and air stations on the islands and it did not begin direct military preparations in the Mandate until the late 1930s. Nevertheless, the territory provided important coaling stations for steam-powered vessels and its possession gave an impetus to the Nanshin-ron doctrine of "southward advance".