# Japanese colonial empire

The territorial conquests of the Empire of Japan in the Western Pacific Ocean and East Asia began in 1895 with its victory over Qing China in the First Sino-Japanese War. Subsequent victories over the Russian Empire (Russo-Japanese War) and the German Empire (World War I) expanded Japanese rule to Taiwan, Korea, Micronesia, Southern Sakhalin, several concessions in China, and the South Manchuria Railway. In 1931, Japan invaded Manchuria, resulting in the establishment of the puppet state of Manchukuo the following year; thereafter, Japan adopted a policy of founding and supporting puppet states in conquered regions. These conquered territories became the basis for the Greater East Asia Co-Prosperity Sphere in 1940.
Including Mainland Japan, colonies, occupied territories, and puppet states, the Empire of Japan at its apex was one of the largest empires in history. The total amount of land under Japanese sovereignty reached 8,510,000 km$^2$ (3,300,000 sq mi) in 1942. By 1943, it accounted for more than 20% of the world's population at the time with 463 million people in its occupied regions and territories.
After Japan was defeated by the Allies in 1945, colonial control from Tokyo over the far-flung territories ended. The extent of Japanese governance was restricted to the naichi (excepting Karafuto Prefecture, which was annexed by the Soviet Union); the Nanpō and Ryūkyū Islands were returned to Japan by the US in 1968 and 1972 respectively.
The territorial expansion of the Japanese colonial empire was marked by aggression towards other nations, with the Japanese committing numerous atrocities and war crimes, killing millions.

## Pre-1895

The first overseas territories that Japan acquired were the islands of its surrounding seas. During the early Meiji era, the Russian Empire established control over the Nanpō, Ryukyu, and Kuril Islands; it also strengthened control of the naichi. However, this effort was less an initial step toward colonial expansion than it was a reassertion of national authority over territories traditionally within the Japanese cultural sphere.

## Acquisition of colonies

At the start of the twentieth century the rate of population increase in Japan was seen as a potential problem for the Japanese government, and colonial expansion into Korea and Manchuria was seen as a possible solution.

### Taiwan

Between 1895 and 1945, Taiwan, including the Penghu Islands, was a colony of the Japanese Empire; following the defeat of Qing China in the First Sino-Japanese War, it ceded Taiwan to Japan under the terms of the Treaty of Shimonoseki. The short-lived Republic of Formosa resistance movement was quickly suppressed by the Japanese military. The fall of Tainan ended organized resistance to Japanese occupation and inaugurated five decades of Japanese rule.
Since Taiwan was Japan's first overseas colony, the central and colonial governments turned their efforts into making the island a "model colony". These resulted in the modernization of the island's economy, infrastructure, industry, public works, and forced assimilation.
In 1945, after the defeat of the Japanese Empire in World War II, Taiwan placed under the control of the Republic of China with the signing of the Japanese Instrument of Surrender. The experience of Japanese rule, Kuomintang rule, and the February 28 Incident of 1947 continues to affect issues such as Retrocession Day, national and ethnic identity, and the Taiwan independence movement.

### Korea

In the late 19th and early 20th centuries, various Western countries competed for influence, trade, and territory in East Asia, and Japan sought to join these modern colonial powers. The newly modernized Meiji government of Japan turned to Korea, then in the sphere of influence of China's Qing dynasty. The Japanese government initially sought to separate Korea from Qing and make Korea a Japanese satellite to further their security and national interests.
In January 1876, Japan employed gunboat diplomacy to pressure Korea, under the Joseon dynasty, to sign the Japan–Korea Treaty of 1876, which granted extraterritorial rights to Japanese citizens and opened three Korean ports to Japanese trade. The rights granted to Japan under this unequal treaty, were similar to those granted to western powers in Japan following the visit of Commodore Perry. Japanese involvement in Korea increased during the 1890s, a period of political upheaval.
Korea was occupied and declared a Japanese protectorate following the Japan–Korea Treaty of 1905; it was annexed in 1910 through the annexation treaty. Korea was renamed Chōsen and remained a part of the Japanese Empire for 35 years; from August 22, 1910, until August 15, 1945, upon the surrender of Japan in the Pacific War. The 1905 and 1910 treaties were officially declared "null and void" by both Japan and South Korea in 1965.

### South Sakhalin

During the 19th century, Russia and Japan vied for control of Sakhalin Island. Following the Meiji Restoration in 1868, Japanese settlers were sent to southern Sakhalin to exploit its resources. Japan ceded southern Sakhalin to Russia in 1875 in exchange for the Kuril Islands under the Treaty of Saint Petersburg. After achieving victory in the Russo-Japanese War, Japan was ceded southern Sakhalin under the terms of the Treaty of Portsmouth. Japan established its colonial government in 1907, whereupon South Sakhalin was renamed Karafuto Prefecture.
Japanese and Korean migrants to the colony developed the fishing, forestry and mining industries. Taking advantage of the Russian Civil War, the Imperial Japanese Army occupied northern Sakhalin between 1920 and 1925; afterwards Japan retained favorable coal and oil concessions therein until 1944. In 1943, Karafuto was elevated to naichi status.
The Soviet Union invaded and annexed Karafuto at the end of World War II.

### South Seas Mandate

Following the outbreak of World War I in 1914, the Japanese Empire declared war on the German Empire and quickly seized the possessions of the German colonial empire in the Pacific Ocean (the Northern Mariana Islands, the Caroline Islands and the Marshall Islands) with virtually no resistance. After the end of the war the Treaty of Versailles formally recognized the Japanese occupation of former German colonies in Micronesia north of the equator. A League of Nations mandate put them under the Japanese administration known as the Nan'yō Agency or South Seas Agency (南洋廳, Nan'yō Chō) and the post of Governor of the South Seas Mandate was created.
The main significance of the South Seas Mandate to Japan was its strategic location, which dominated the sea lanes across the Pacific Ocean and provided convenient provisioning locations for ships. During the 1930s, the Imperial Japanese Navy began construction of airfields, fortifications, ports, and other military projects on the South Seas Mandate islands, viewing them as "unsinkable aircraft carriers" with a critical role to play in the defense of the Japanese home islands against potential invasion by the United States. The islands became important staging grounds for Japanese air and naval offensives during the Pacific War but were lost to American military action between 1943 and 1945. The League of Nations mandate was formally revoked by the United Nations on July 18, 1947, according to Security Council Resolution 21, making the United States responsible for administration of the islands under the terms of a United Nations trusteeship agreement which established the Trust Territory of the Pacific Islands.

### Manchuria

After emerging victorious against Qing China in the First Sino-Japanese War, Japan was ceded the southern part of the Liaodong Peninsula under the terms of the Treaty of Shimonoseki. Diplomatic pressure from Russia, Germany, and France forced Japan to quickly relinquish the territory, which allowed Russia to lease it from China in 1898. In 1905, Russia was defeated in the Russo-Japanese War; under the terms of the Treaty of Portsmouth, Russia returned the Liaodong Peninsula to Japan, whereupon it was renamed the Kwantung Leased Territory. A governor and an Imperial Japanese Army garrison were established, the latter becoming the Kwantung Army in 1919.
As a result of Russia's defeat, it also lost influence in Manchuria, which allowed Japan to take its place. In 1906, Japan laid the South Manchuria Railway to Ryojun. Japan temporarily occupied Outer Manchuria in 1918, but returned it to the Soviet Union in 1922. Manchuria came under the control of the Chinese warlord Zhang Zuolin during the warlord period in China. He initially had Japanese backing, but the Kwantung Army found him too independent; he was assassinated in 1928.
The Japanese invasion of Manchuria took place in 1931 following the Mukden Incident, a staged event engineered by Japanese military personnel from the Kwantung Army as a pretext for invasion. The region was subsequently separated from Chinese control and the Japanese-aligned puppet state of Manchukuo was created. The last Emperor of China, Puyi, was installed as head of state in 1932, and two years later he was declared Emperor of Manchukuo. The city of Changchun was renamed Xinjing and became the capital of Manchukuo. An imperial palace was specially built for the emperor. He was, however, nothing more than a figurehead and real authority rested in the hands of the Japanese military officials. The Manchu ministers all served as front-men for their Japanese vice-ministers, who made all decisions. Anti-Japanese Volunteer Armies were organized by the Chinese in Manchuria and the pacification of Manchukuo required a war lasting several years.
During the 1930s the Japanese colonized Manchukuo. With Japanese investment and rich natural resources, the economy of Manchukuo experienced rapid economic growth. Manchukuo's industrial system became one of the most advanced, making it one of the industrial powerhouses in the region. Manchukuo's steel production exceeded Japan's in the late 1930s. The Japanese Army initially sponsored a policy of forced industrialization modeled after the Five Year Plan in the Soviet Union but subsequently private capital was used in a very strongly state-directed economy. There was progress in the area's social systems and many Manchurian cities were modernized. Manchukuo issued banknotes and postal stamps, and several independent banks were founded. The Chinese Eastern Railway was bought from the Soviet Union in 1935. Traditional lands were taken and redistributed to Japanese farmers with local farmers relocated and forced into collective farming units over smaller areas of land.
During this period Manchukuo was used as a base from which to invade China. In the summer of 1939, a border dispute between Manchukuo and the Mongolian People's Republic resulted in the Battle of Khalkhin Gol. During this battle, a combined Soviet Army and Mongolian force defeated the Japanese Kwantung Army (Kantōgun) supported by limited Manchukuoan forces. The Soviet Union declared war on Japan on 8 August 1945 under the agreement at the Yalta Conference and invaded Manchukuo from the north through Outer Manchuria and Mongolia. This was called the Manchurian Strategic Offensive Operation. The Army of Manchukuo was defeated and the Emperor was captured by Soviet forces. Most of the 1.5 million Japanese who had been left in Manchukuo at the end of World War II were ultimately sent back to their homeland in 1946–1948 by U.S. Navy ships in the Japanese repatriation from Huludao.

## World War II

| Territory | Japanese name | Date | Population est.(1943) | Notes |
| Japan | Naichi (內地) | 1868-1945 | 72,000,000 | Present-day Japan, South Sakhalin, Kuril, and Ryukyu Islands |
| Karafuto/South Sakhalin | Karafuto-chō (樺太廳) | 1905-1943 | 406,000 | Ceded by the Russian Empire to Japan |
| Korea | Chōsen (朝鮮) | 1910-1945 | 25,500,000 | |
| Taiwan | Taiwan (臺灣) | 1895-1945 | 6,586,000 | Ceded by Qing China to Japan |
| Mainland China | Shina (支那) | 1931–1945 | 200,000,000 (est.) | Manchukuo 50 million (1940), Rehe, Kwantung Leased Territory, Jiangsu, Shanghai, Shandong, Hebei, Beijing, Tianjin, plus parts of : Guangdong, Guangxi, Hubei, Hunan, Fujian, Guizhou, Inner Mongolia |
| Hong Kong | Honkon (香港) | December 25, 1941 – August 15, 1945 | 1,400,000 | Hong Kong |
| East Asia (subtotal) | Higashi ajia (東亞細亞) or Tō-a (東亞) | – | 306,792,000 | |
| Vietnam | An'nan (安南) | September 1940 – August 1945 | 22,122,000 | As French Indochina |
| Cambodia | Kambojia (カンボジア) | August 1941 – August 1945 | 3,100,000 | As French Indochina, Japanese occupation of Cambodia |
| Laos | Raosu (ラオス) | September 1940 – August 1945 | 1,400,000 | As French Indochina, Japanese occupation of Laos |
| Thailand | Tai (泰/タイ) | December 8, 1941 – August 15, 1945 | 16,216,000 | Independent state, but allied with Japan |
| Malaysia | Maraya (マラヤ) or Marē (マレー), Kita Boruneo (北ボルネオ) | December 8, 1941 – September 2, 1945 (Malaya), December 1941 – September 1945 (Sarawak, Brunei, Labuan, North Borneo) | 4,938,000 plus 39,000 (Brunei) | As Malaya, British Borneo, Brunei |
| Philippines | Firipin (比律賓/フィリピン) or Hitō (比島) | 1942 - 1945 | 17,419,000 | Philippines |
| Dutch East Indies | Higashi indo (東印度) | 1942 –1945 | 72,146,000 | As Dutch East Indies and West Sumatra |
| Singapore | Shōnan-tō (昭南島) | February 15, 1942 – September 12, 1945 | 795,000 | Singapore |
| Burma | Biruma (ビルマ) | 1942–1945 | 16,800,000 | Burma |
| East Timor | Higashi chimōru (東チモール) | February 19, 1942 – September 11, 1945 | 450,000 | Portuguese Timor |
| Southeast Asia (subtotal) | Tō-nan ajia (東南亞細亞) | – | 155,452,000 | |
| Manipur | Manipurū (マニプール) | October 21, 1943 – August 18, 1945 | 525,000 | Azad Hind (also independent but Japanese-allied) |
| South Asia (subtotal) | Minami ajia (南亞細亞) | - | 525,000 | |
| New Guinea | Nyūginea (ニューギニア) | December 1941 – 1945 | 1,400,000 | As Papua and New Guinea |
| Guam | Ōmiya Island (大宮島) | December 10, 1941 – August 10, 1944 | | from Guam |
| South Seas Mandate | Nan'yō guntō (南洋群島) | 1919–1945 | 129,000 | from German Empire |
| Nauru | Nauru (ナウル) | August 26, 1942 – September 13, 1945 | 3,000 | from United Kingdom, Australia and New Zealand |
| Wake Island | Ōtori Island (大鳥島) | December 23, 1941 – September 4, 1945 | nil | United States |
| Kiribati | Kiribasu (キリバス) | December 1941 – January 22, 1944 | 28,000 | from the Gilbert Islands |
| Pacific Islands (subtotal) | – | – | 1,433,000 | |
| Total population | – | – | 464,202,000 | |
Disclaimer: Not all areas were considered part of the Empire of Japan, but within its sphere of influence, included separately for demographic purposes. Sources: POPULSTAT Asia Oceania
Other islands occupied by Japan during World War II:
* Andaman Islands (India) – March 29, 1942 – September 9, 1945
* Christmas Island (Australia) – March 1942 – October 1945
* Attu and Kiska (Alaska, United States) – June 3, 1942 – August 15, 1943

### Areas attacked but not conquered

* Kohima (India)
* Dornod (Khalkhin Gol, Mongolia)
* Midway Atoll (United States)

### Raided without immediate intent of occupation

* Air raids
** Pearl Harbor (Hawai'i, United States)
** Colombo and Trincomalee (Sri Lanka)
** Kolkata (India)
** Chittagong (Bangladesh)
** Air raids on Australia, including:
*** Broome (Western Australia, Australia)
*** Darwin (Northern Territory, Australia)
*** Townsville (Queensland, Australia)
** Dutch Harbor (Alaska, United States)
** Lookout Air Raids (Oregon, United States)
* Naval bombardment by submarine
** British Columbia (Canada)
** Santa Barbara (California, United States)
** Fort Stevens (Oregon, United States)
** Newcastle (New South Wales, Australia)
** Gregory (Western Australia, Australia)
* Midget sub attack
** Sydney (New South Wales, Australia)
** Diego Suarez (Madagascar)

## Administration

A shortage of Japanese administrators led to the establishment of colonial puppet states and the promotion of indigenous elites in the territories which came under Japanese control in the 1940s.

## Economic development

According to Atul Kohli, the David K.E. Bruce Professor of International Affairs and Professor of Politics and International Affairs at Princeton, "the Japanese made extensive use of state power for their own economic development and then used the same state power to pry open and transform Korea in a relatively short period of time". Japan was "decisive in altering both the nature of the Korean state and the relationship of this state to various social classes." How the Japanese centralized bureaucratic style of government was transferred to Korea; how they developed Korean human capital by a considerable expansion of education; how the Japanese invested heavily in infrastructure. Kohli's conclusion is that "the highly cohesive and disciplining state that the Japanese helped to construct in colonial Korea turned out to be an efficacious economic actor. The state utilized its bureaucratic capacities to undertake numerous economic tasks: collecting more taxes, building infrastructure, and undertaking production directly. More important, this highly purposive state made increasing production one of its priorities and incorporated property-owning classes into production-oriented alliances". This sprawling bureaucratic state continued post-World War II and after the Korean War. Japan's early colonial industrialisation of Korea also made it easier to rebuild after the Korean War, because there was no need to begin industrialisation ab initio. Examining Korea's policies and achievements in the 1960s and 1970s, Kohli states that during this period the country was firmly heading towards "cohesive-capitalist development, mainly by re-creating an efficacious but brutal state that intervened extensively in the economy". South Korean economic development was not market-driven—rather the "state intervened heavily to promote exports, using both market and non-market tools to achieve its goals".