Before and during World War II, the Empire of Japan created a number of puppet states that played a noticeable role in the war by collaborating with Imperial Japan. With promises of "Asia for the Asiatics" cooperating in a Greater East Asia Co-Prosperity Sphere, Japan also sponsored or collaborated with parts of nationalist movements in several Asian countries colonised by European empires, the Soviet Union, and the United States.Total War: Causes and courses of the Second World War, by Peter Calvocoressi and Guy Wint, Penguin Books, 1972 (1st edition) , The War in Asia, chapter 9, pp. 683–685. The Japanese recruited volunteers from several occupied regions and also from among Allied prisoners-of-war.The Labour Recruitment of Local Inhabitants as Rōmusha in Japanese-Occupied South East Asia, Takuma Melber. Part of: Special Issue: Conquerors, Employers and Arbiters: States and Shifts in Labour Relations, 1500–2000, International Review of Social History, Volume 61, Special Issue S24: Published online by Cambridge University Press: 1 December 2016.

Some of the leaders in various Asian and Pacific territories cooperated with Japan as they wanted to gain independence from the European colonial overlords, as seen in Burma and Indonesia. Some other collaborators were already in power of various independent or semi-independent entities, such as Plaek Phibunsongkhram's regime in Thailand, which desired to become a major player in Asian politics but were restrained by geopolitics, and the Japanese maximised it to some extent. Others believed Japan would prevail, and either wanted to be on the winning side, or feared being on the losing one.

Like their German and Italian counterparts, the Japanese recruited many volunteers, sometimes at gunpoint, more often with promises that they later broke, or from among prisoners-of-war trying to escape appalling and frequently lethal conditions in their detention camps. Other volunteers willingly enlisted because they shared fascist or pan-Asianist ideologies.

Japanese colonial empire Korea

Taiwan

British Empire and Commonwealth Burma

The Japanese invaded Burma because the British had been supplying China in the Second Sino-Japanese War along the Burma Road.Seagrave, Gordon S., Burma Surgeon, W. W. Norton & Company, New York, 1943 Burmese nationalists known as Burma Independence Army hoped for independence.Micheal Clodfelter. Warfare and Armed Conflicts: A Statistical Reference to Casualty and Other Figures, 1500–2000. 2nd Ed. 2002 . p. 556Werner Gruhl, Imperial Japan's World War Two, 1931–1945 Transaction 2007 (Werner Gruhl is former chief of NASA's Cost and Economic Analysis Branch with a lifetime interest in the study of the First and Second World Wars.) They were later transformed into the Burma National Army as the armed forces of the State of Burma. Minority groups were also armed by the Japanese, such as the Arakan Defense Army and the Chin Defense Army.

Ceylon (Sri Lanka)

Hong Kong

Hong Kong was a British crown colony before its occupation by the Japanese. During the Japanese rule, former members of the Hong Kong Police Force, including Indians and Chinese, were recruited into the Kempeitai police force.Carroll, John Mark. (2007). A concise history of Hong Kong.. pp. 123–125, 129.

India

The Indian Legion (Legion Freies Indien, or Indische Freiwilligen-Legion der Waffen-SS) was created in August 1942, recruiting chiefly from disaffected British Indian Army prisoners of war captured by Axis forces in the North African campaign. Most were supporters of the exiled nationalist and former president of the Indian National Congress Subhas Chandra Bose. The Royal Italian Army formed a similar unit of Indian prisoners of war, the Battaglione Azad Hindoustan. A Japanese-supported puppet state known as the Azad Hind was also established with the Indian National Army as its military force.

Iraq

One of Iraq's most prominent politicians, Taha al-Hashimi, was pro-Japanese and stressed that the Arab world should look to Japan as a role model.https://repository.kulib.kyoto-u.ac.jp/dspace/handle/2433/210345 In 1941, elements of the Iraqi military led by four Colonels, Salah al-Din al-Sabbagh, Kamil Shabib, Fahmi Said, and Mahmud Salman, toppled the Hashemite monarchy and installed a pro-Axis government with Taha al-Hashimi serving as the Prime Minister. Japan, one of the three main Axis powers, supported the group as part of its strategy to improve relations with the Islamic world, although geographical distance meant its support was merely symbolic.

Malaya

After occupying British Malaya, Japanese occupation authorities reorganized the disbanded British colonial police force and created a new auxiliary police. Later on, a 2,000-men strong Malayan Volunteer Army and a part-time Malayan Volunteer Corps were created. Local residents were also encouraged to join the Imperial Japanese Army as auxiliary Heiho. There was a Railway Protection Corps as well.

Straits Settlements

The British territory of the Straits Settlements (Singapore, Malacca, Penang and Dindings) came under Japanese occupation after the fiasco suffered by Commonwealth forces at the Fall of Singapore. The Straits Settlements Police Force came under the control of the Japanese and all vessels owned by the Marine Police were confiscated.

China

The Japanese had previously set up several puppet regimes in occupied Chinese territories. The first was Manchukuo in 1932, under former Chinese emperor Puyi,under the reign title Datong. Datong, Wade-Giles: Ta-tung; 大同 then the East Hebei Autonomous Government in 1935. Similar to Manchukuo in its supposed ethnic identity, Mengjiang (Mengkukuo) was set up in late 1936. Wang Kemin's collaborationist Provisional Government was set up in Beijing in 1937 following the start of full-scale military operations between China and Japan, and another puppet regime, the Reformed Government of the Republic of China, in Nanjing in 1938.

The Wang Jingwei collaborationist government, established in 1940, "consolidated" these regimes, though in reality neither Wang's government nor the constituent governments had any autonomy, although the military of the Wang Jingwei regime was equipped by the Japanese with planes, cannons, tanks, boats, and German-style stahlhelm, which were already widely used by the National Revolutionary Army, the "official" army of the Republic of China.

The military forces of these puppet regimes, known collectively as the Collaborationist Chinese Army, numbered more than a million at their height, with some estimates that the number exceeded 2 million conscriptees. Many collaborationist troops originally served warlords of the National Revolutionary Army who had defected when facing both Communists and Japanese. Although the collaborationist army was very large, its soldiers were very ineffective compared to NRA soldiers, and had low morale because they were considered "Hanjian". Some collaborationist forces saw battlefields during the Second Sino-Japanese War, but most were relegated to behind-the-line duties.

The Wang Jingwei government was disbanded after the Japanese surrendered to Allies in 1945, and Manchukuo and Mengjiang were destroyed in the Soviet invasion of Manchuria.

Inner Mongolia

Manchuria

Xinjiang (Chinese Turkestan) Japan attempted to create an Islamic state spanning from Xinjiang to Soviet Central Asia during the Kumul Rebellion of 1931-1934. During World War II, Japanese agents were again active in both Xinjiang and Soviet Central Asia, where the Japanese attempted to foster rebellions among Muslim population against both China and the Soviet Union.

Dutch East Indies (Indonesia)

Following its swift victory in the Dutch East Indies campaign of 1941–1942, Imperial Japan was welcomed as a liberator by much of the native population of the Dutch East Indies (present-day Indonesia), and especially by the Indonesian nationalists who since the early 20th century had begun developing a national consciousness. In the wake of the Japanese advance, rebellious Indonesians across the archipelago killed scores of European and pro-Dutch civilians (in particular from the Chinese community) and informed the invaders on the whereabouts of others, 100,000 of whom would be imprisoned in Japanese-run internment camps alongside 80,000 American, British, Dutch, and Australian prisoners of war. Unlike in occupied French Indochina, where Imperial Japan worked alongside the French colonizer, the Japanese supplanted the Dutch administration of the East Indies and elevated native elites willing to work with them to power, fueling Indonesian hopes of future self-rule. Imperial Japan imposed a strict occupation regime on the archipelago, however, as to them the value of the archipelago lay mostly in its ample resources for the war effort (specifically oil, tin, and bauxite) and their initial use for the nationalists only extended to the pacification and organization of the sizeable population of Java.

During the occupation of the Dutch East Indies, Sukarno and Mohammad Hatta, respectively the inaugural president and vice president of the future Republic of Indonesia, became promoters of the Japanese forced labor scheme through the Center of the People's Power (; Putera) and mobilized workers for Japanese production and construction projects across Southeast Asia, such as the strategic railways on Sumatra and West Java, and along the Burma–Thailand border. In total, 4 to 10 million Indonesian laborers were recruited and some 270,000 to 500,000 Javanese were sent abroad, of whom 70,000 to 135,000 returned after the war. In November 1943, the Japanese flew Sukarno and Hatta to Tokyo to receive the Order of the Rising Sun from Emperor Hirohito for their services. Similarly, Indonesia's second president Suharto and first commander of the Indonesian National Armed Forces Sudirman began their military careers in the Japanese-sponsored Defenders of the Homeland (; PETA), which alongside the auxiliaries of the () was to assist the Imperial Japanese military in fighting off the expected Allied return to the East Indies. Hundreds of thousands served in Japanese organizations such as the propaganda institution (), the youth movement (), and the auxiliary police forces of the ().

As its fortunes turned, Imperial Japan became faced with growing resistance to its increasingly repressive occupation and began catering to the Indonesian desire for self-rule. Already in September 1943, the Javanese Central Advisory Council (, ) had been created around Sukarno, Hatta, Ki Hajar Dewantara, and Mas Mansur, and expanded to include notables such as Rajiman Wediodiningrat and Ki Bagus Hadikusumo. Sumatran representation under Mohammad Syafei, Abdul Abas, and Teuku Nyak Arif would follow nearly two years later and included established nationalists such as Djamaluddin Adinegoro and Adnan Kapau Gani. In January 1944, the Center of the People's Power was replaced by the less overtly Japanese-controlled (; ) in a renewed attempt to increase Javanese labor and produce for the Japanese war effort. A paramilitary youth wing, the (; ), would be founded in August. In July 1944, Japanese prime minister Hideki Tojo was forced to resign and on 7 September his replacement Kuniaki Koiso made a promise of independence for "the East Indies" (). In spite of the deteriorating military situation and a disastrous famine on Java, war enthusiasm had returned to the extent that the suicide attack corps (; ) could be formed on 8 December 1944.