Collaboration with Imperial Japan

Wang Jingwei with officers of the Collaborationist Chinese Army

The Japanese had previously set up several puppet regimes in occupied Chinese territories. The first was Manchukuo in 1932, under former Chinese emperor Puyi,[12] 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.

Japanese soldiers primarily used Laos to stage attacks on Nationalist China.[13]

On 22 September 1940, Vichy France and the Empire of Japan signed an agreement allowing the Japanese to station no more than 6,000 troops in French Indochina, with no more than 25,000 troops transiting the colony. Rights were given for three airfields, with all other Japanese forces forbidden to enter Indochina without Vichy's consent. Vichy signed the Joint Defense and Joint Military Cooperation treaty with Japan on 29 July 1941.[14] It granted the Japanese eight airfields, allowed them to have more troops present, and to use the Indochinese financial system, in return for a fragile French autonomy.

The French colonial government had largely stayed in place, as the Vichy government was on reasonably friendly terms with Japan. The Japanese permitted the French to put down nationalist rebellions in 1940.

The Japanese occupation forces kept French Indochina under nominal rule of Vichy France until March 1945, when the French colonial administration was overthrown, and the Japanese supported the establishment of the Empire of Vietnam, Kingdom of Kampuchea and Kingdom of Laos as Japanese puppet states. Vietnamese militia were used to assist the Japanese.[15] In Cambodia, the ex-colonial Cambodian constabulary was allowed to continue its existence, though it was reduced to ineffectuality. A plan to create a Cambodian volunteer force was not realized due to the Japanese surrender.[16] In Laos, the local administration and ex-colonial Garde Indigène (Indigenous Guard, a paramilitary police force) were re-formed by Prince Phetsarath, who replaced its Vietnamese members with Laotians.[13] The Hmong Lo clan supported the Japanese.[13]

Some Indonesians initially welcomed the Japanese as liberators.[17] Among Indonesians to receive Japanese imperial honours from Hirohito in November 1943 were Sukarno and Mohammad Hatta. Sukarno actively recruited and organised Indonesian Rōmusha forced labour.[18] They respectively became the founding President of Indonesia and Vice President of Indonesia in August 1945.

The Second Philippine Republic was a puppet state established by Japanese forces after occupying the Philippines, which relied on the re-formed Bureau of Constabulary[19] and the Makapili militia to police the occupied country and fight the local resistance movement and the Philippine Commonwealth Army. The president of the republic, Jose P. Laurel, had his presidential guard unit that was recruited from the ranks of the collaborationist government. When the Americans closed in on the Philippines in 1944, the Japanese began to recruit Filipinos, who mostly served in the Imperial Japanese Army and actively fought until Japan's surrender. After the war, members of Makapili and other civilian collaborators were subject to harsh treatment by both the government and civilians, because their actions had led to the capture, torture, and execution of many Filipinos.[20]

Portugal was neutral during the war, but its colony in Timor was occupied by the Japanese to expel Australian troops.[21] The Japanese used the population for forced labor.[21] Local militiamen were organized into "black columns" to help Japanese forces fight Allies.[22]

The Japanese recruited volunteers from several occupied regions and from among POWs.[23]