[This subject has fascinated me ever since I read reports that the Japanese genius and war criminal Colonel Tsuji Masanobu had spent his last years in Vietnam, helping defeat the Americans. At last someone has done serious research into the subject. As a French scholar, using French archives, Christopher Goscha concentrated on the years 1945-1950, and there is of course no proof that any of the individuals he mentions were still serving with the North Vietnamese or Viet Cong during the "American War." What follows is condensed, with Prof. Goscha's permission, from his article "Belated Asian Allies," which appears in A Companion to the Vietnam War, edited by Young Buzzanco and published by Blackwell in 2002. -- Dan Ford]
Belated Asian Allies
Goscha estimates that perhaps 5,000 Japanese stayed behind in Vietnam in the fall of 1945. (The translator renders their status as "deserters," but I don't think that's honest. How can you desert from an army that has surrendered?) Famously able to subordinate the means to the end, the Communists naturally put them to use in their war against the French. As Goscha points out, the Viet Minh had very little experience in warfare or government, as opposed to guerilla resistance of the sort they had used against the occupying Japanese. They would have been glad of the expertise available in the left-behind Japanese population, both military and civilian.
Vietnam was divided at the 16th parallel by the victorious Allies, with the Chinese occupying the north and the British occupying the south. The Chinese gave the Viet Minh considerable freedom of action, while the British brought in French troops to relieve them of the burden of occupation; the French of course moved quickly to put down any independence movement.
The first Japanese aid came in the form of arms: in the north, Vo Nguyen Giap equipped his troops with French weapons that the Japanese had issued to its puppet Indochinese Guard. Japanese weapons made their way into the black market soon after the surrender. It wasn't long before Japanese soldiers and officers also became available: there was no immediate way home for these men, even if they wanted to go. They hadn't been defeated in the field; they couldn't understand why the Emperor had ended the war; they had nothing to greet them at home but shame and desolation. Many had Vietnamese wives or girlfriends. When the war ended, they thought of themselves in the tradition of the ronin or leaderless samurai warriors. Like the ronin, they simply gravitated toward whatever employer was willing to hire them.
And the Viet Minh wanted them, the officers and NCOs particularly, as training cadres. In September 1945, there were about 50,000 Japanese soldiers and civilians in northern Vietnam; by December 1946, about 32,000 had been repatriated and 3,000 escaped to the island of Hainan, leaving 15,000 still in the country. Perhaps a third of these, Goscha believes, may have joined the Viet Minh as cadre, combat troops, or civilian experts. In the British-occupied south, with the French returning and pressing the Viet Minh hard, a much larger proportion of the Japanese garrison was repatriated; Goscha estimates that only a few thousand remained in the summer of 1946, and that perhaps only a few hundred actually joined the Communist forces. (Apparently a larger number simply melted into the population as farmers and shop-keepers.)
In Thai Nguyen province, the Japanese apparently ran an arms factory. In Hanoi, a western-educated Japanese scholar named Kiyoshi Komatsu directed the Viet Minh's "International Committee for the Aid and Support of the Government of the DRV." In Quang Ngai, a Viet Minh officers' school had six Japanese officers on the faculty; in southern Trung Bo province, 36 out of 50 military instructors were Japanese. Major Ishii Takuo, a young officer of the 55th Division in Burma, deserted in Cambodia in December 1945 with several comrades and made his way to Vietnam, where he became a colonel in the Viet Minh, provisional head of the Quang Ngai military academy, and later "chief advisor" to Communist guerrillas in the south. Some specialists, including doctors and ordnance experts, were forced to work for the Viet Minh against their will. The French identified eleven Japanese nurses and two doctors working for the Viet Minh in northern Vietnam in 1951.
"One of the results of the Japanese presence in the Viet Minh army was an increase in French losses at the beginning of the war," Goscha writes. During the first battles in the north, Japanese soldiers served in the front lines. In Hue in 1947, the French reported battling a Japanese assault force of 150 men. Also in 1947, Colonel Ishii helped set up an ambush that killed upwards of 70 French soldiers.
Koshiro Iwai led Vietnamese units into battle and led commando raids behind French lines; by 1949 he was a Viet Minh battalion deputy commander. Later he became a planner for the 174th Regiment, helping the Viet Minh to employ their newly acquired Chinese cannon.
In 1951, the Viet Minh began to repatriate their Japanese (and European) helpers via China and Eastern Europe. After the Geneva Accords of 1954, which divided Vietnam into two halves, 71 Japanese left the Viet Minh and went home, and others returned over the years. "A handful would remain in Vietnam well into the 1970s," Goscha writes. "Others would never return." This doesn't necessarily mean they helped in the war against the Americans; more likely, these stay-behinds had simply gone native.
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