“As the war continued, Japan’s outnumbered military relied heavily on these foreign auxiliaries and volunteers to fight against partisans and secure the hinterland of their fast-growing collection of occupied territories.”

By Florian Heydorn

WHEN JAPAN ENTERED the Second World War and began its conquest of the British and Dutch colonies its soldiers did not fight alone.

Even before the outbreak of war, Tokyo’s intelligence officers reached out to nationalists and freedom fighters across the Far East while forcefully cultivating for itself the image of a rising power striving to bring pride to all Asians.

With imminent offensives at hand, Japan’s pan-Asian and anti-colonial propaganda attracted activists and ordinary people alike, who came to see Japan as a liberator from European oppression. And despite how harsh life became under Japanese occupation, thousands in these territories were still willing to fight under the banner of the Rising Sun in hopes of one day achieving independence.

As the war continued, Japan’s outnumbered military relied heavily on these foreign auxiliaries and volunteers to fight against partisans and secure the hinterland of their fast-growing collection of occupied territories.

Here are five of Japan’s Asian allied armies, many in the West have probably never heard of.

Inner Mongolian Army

Among the first foreign auxiliaries to side with Imperial Japan were nationalists in Inner Mongolia.

Although initial contact dates back to the 1920s, when Japan conquered Manchuria in 1932 talks intensified. Prince Demchugdongrub, an ambitious Mongol leader, sided with Japanese agents as part of a campaign to break Inner Mongolia away from China. He eventually became leader of the puppet state of Mengjiang in 1938, but finally had to accept the incorporation of his territories as an autonomous province into the wider Japanese-run Reorganized Government of China in 1940.

In 1936, Demchugdongrub suffered a major defeat in an ill-fated attempt to expand into northern China. He suffered heavy losses again during a joint Japanese-Mongol offensive at the beginning of the Second Sino-Japanese War one year later. The Mongol army was subsequently reorganized several times and by 1945 would consist of two cavalry divisions, four light infantry divisions and three separate Chinese brigades with 10,000 men in total.

Yet from the start, its operational readiness was limited. Lack of training and modern equipment led to severe limitations of the Mongol’s combat capabilities and manoeuvrability. Armed with outdated rifles, only a few light machine guns and a small assortment of field artillery pieces, it was entirely without mobile or heavy weaponry. As such, it could only act as an auxiliary force. When the Soviet Union invaded Manchuria and Inner Mongolia in August of 1945 the few local units that actually engaged the Red Army were easily swept aside.

Burmese National Army

The Japanese paid little attention to Burma before 1940, when Staff Officer Keji Suzuki was tasked with devising a strategy for South East Asia.

In September of that year, he made contact with Burmese nationalist Aung San and convinced him and his followers to allow Japan to train the faction for espionage and guerrilla warfare. The Burmese Independence Army was officially founded on Dec. 28, 1941 and took part in the Japanese conquest of the region, rallying support from the local population and subsequently growing to 23,000 men by May of 1942.

Inexperienced, disorganized and only trained for irregular warfare, the force committed atrocities against Indians and ethnic minorities in Burma, but suffered heavy casualties in fighting against the British army in 1942 and ’43.

Soon after the campaign ended, tensions grew between Tokyo and Burma’s nationalists over the question of independence. In August of 1943, Burma finally declared itself an independent nation, after which the BIA was disbanded and rebuilt as Burmese National Army. Aung San still commanded more than 15,000 trained and well-equipped light infantry, but the Japanese held their grip, subjugated the population and granted only limited sovereignty.

Dissatisfied and increasingly sceptical about Japan’s ability to win the war, Aung San formed the Anti-Fascist Organization with leftist political groups in autumn 1944 and opened talks with the British.

When in March 1945 the BNA was ordered to march against the advancing Allies in Central Burma, the time had come to rise against the Japanese.

The BNA turned against their occupiers and again rallied a nation-wide rebellion, cutting of supply lines and seizing control of huge parts of the Japanese-held hinterland.

After the war BNA veterans, along with veterans of British colonial units, formed the core of the new Burmese army. Aung San became a leading figure in the negotiations with Great Britain about independence before his murder in 1947.

Indian National Army

The Indian National Army is distinct among Japan’s Asian auxiliaries. Unlike the case with Tokyo’s other territorial partners, the empire didn’t conquer India. In fact, it never even considered the subcontinent as a part of its Greater East Asia Co-Prosperity Sphere.

But, as the bulk of British forces in South East Asia were made up of Indians, Japan’s military saw an opportunity to weaken their adversary’s defences by supporting Indian nationalist factions.

Intelligence officers contacted exiled Indians in Thailand prior to 1941 and soon after the fall of Burma and Malaya, Tokyo began recruitment of Indian POWs.

Soon, an Indian National Army under Mohan Singh was raised and an Indian Independence League (IIL) in Bangkok under the Bengali Rash Behari Bose was established. The cooperation would be short-lived, mainly due to a reluctance on the part of ILL leadership to take open military action against Great Britain without an order from the Indian National Congress.

Not all Indian nationalists were so hesitant. In the spring of 1943, a radical named Subhas Chandra Bose returned to Asia from Nazi Germany after successfully raising an Indian Legion for the Wehrmacht.

Subhas Chandra Bose soon came to terms with Japan and declared the independence of a Singapore-based Provisional Government of Free India in October 1943.

Eventually, the Second INA consisted of three lightly armed infantry divisions with 40,000 men. A small corps of volunteers even underwent aviation training in Japan.

The INAs 1st and 2nd divisions even took part in the India Offensive in spring 1944 and saw heavy fighting in Arakan and at Imphal. But their initial plans to advance into the Northern Indian Plains and ignite a guerrilla war proved to be unrealistic. British-Indian soldiers didn’t defect as expected and the Japanese offensive was driven back. Later, the INA fought alongside the Japanese in Burma until the end of the war.

Indonesian Volunteer Army

Like in Burma, the Japanese could rely on anti-colonial Indonesian nationalists when they began their invasion of the Dutch East Indies in early 1942. Japan’s pan-Asian propaganda efforts fell on fertile ground and within weeks of the occupation, Dutch officials were replaced with Indonesians or Japanese administrators.

But unlike in Burma or India, no promises for future independence, however vague they might have been, where initially made.

Sympathy for Japan among Indonesia’s nationalist factions deteriorated quickly as Tokyo’s aim seemed to be the outright annexation of territory. Policies of forced labour, torture and arbitrary executions further turned locals against the occupiers, as did Japan’s tight control over food, resources and local manpower.

Nevertheless, Japanese officials still encouraged Indonesian nationalists to support their administration, like later leading politicians Sukarno and Mohammad Hatta, who saw collaboration as a means to spread nationalist ideas to the population.

In October 1943, the Japanese even founded the Pembela Tanah Air, an Indonesian volunteer militia that would help to defend the islands against the Allies and secure vital installations.

By the end of the war, the army consisted of 57,000 men in 69 battalions stationed on Java and Sumatra, although it maintained only light equipment and had no aircraft or armoured vehicles.

When Sukarno declared Indonesia’s Independence on Aug. 17, 1945, the Pembela Tanah Air was dissolved having seen no fighting. Many of its members and officers, like Suharto, would later form the core forces of the new Indonesian military.

Collaborationist Chinese Army

Astonishingly, the greatest contribution to Japan’s war efforts came from China – the country that arguably suffered the most under Tokyo’s expansionism.

As early as 1937, Japan had founded local and regional puppet governments and began to build up local police and fighting forces. In 1940, all of these were merged into the Reorganized Government of the Republic of China under Wang Jingwei, a long rival of China’s generalissimo Chiang Kai-Chek.

Japan kept strict control over the local regime’s authority until a general agreement was reached in 1943, after which Japan finally recognized Jingwei’s government as the only Chinese administration to be dealt with.

In 1943, this new Collaborationist Chinese Army had 43 divisions, with an estimated strength between 300,000 and a half-million men, although only Jingwei’s three Guard Divisions with 30,000 men and the army of his close associate Zhou Fohai with 20,000 men were considered to be the most reliable and combat ready.

The rest of the forces were under the command of former warlords, whose loyalty was suspect by both Jingwei and Tokyo. None received modern weapons and were mainly used in anti-partisan operations or for the defence of military installations, thus freeing Japanese troops for offensive operations elsewhere.

Only Jingwei’s Guard Divisions received a handful of Japanese tanks and armoured vehicles. When the Japanese occupation collapsed in 1945, these units mounted a campaign against the Chinese Communists. Soon enough, the army was disbanded, with most of the battalions re-joining the Kuomintang.

Additionally, pro-Japanese Chinese also established an air force and a navy. But as the former relied heavily on defected Chinese Nationalist pilots whom the Japanese mistrusted and were not willing to arm with fighter planes, it conducted training and transport missions only.

The navy maintained a small fleet of Chinese vessels, which were captured by Japan at the beginning of the war, with which they conducted mostly coast guard duties.

Further Reading:

Allen, Louis: Burma: The Longest War 1941-45, Darlington 1984.

Barett, David: Chinese Collaboration with Japan. 1932–1945: The Limits of Accommodation, Standford 2002.

Lebra, Joyce C.: Jungle Alliance, Japan and the Indian National Army, Singapore 1971.

Sunhaussen, Ulf: The Road to Power: Indonesian Military Politics 1945-1967, Oxford 1982.