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The units of the 1st Area Army proved to be no match for the Red Army when the Soviet Union invaded Manchukuo at the end of World War II. Without adequate armor, ammunition or leadership, many units broke and fled, or surrendered en masse. Many surviving soldiers of the 1st Area Army, including its commanding officer General Seiichi Kita, became prisoners in Siberia and other parts of the Soviet Union after the surrender of Japan on August 15, 1945.
Glantz, The Soviet Strategic Offensive in Manchuria, 1945
Frank, Downfall: The End of the Imperial Japanese Empire
References
Frank, Richard B (1999). Downfall: The End of the Imperial Japanese Empire. New York: Random House. ISBN0-679-41424-X.
Glantz, David (2003). The Soviet Strategic Offensive in Manchuria, 1945 (Cass Series on Soviet (Russian) Military Experience, 7). Routledge. ISBN0-7146-5279-2.
Jowett, Bernard (1999). The Japanese Army 1931-45 (Volume 2, 1942-45). Osprey Publishing. ISBN1-84176-354-3.
Madej, Victor (1981). Japanese Armed Forces Order of Battle, 1937-1945. Game Publishing Company. ASIN: B000L4CYWW.
Marston, Daniel (2005). The Pacific War Companion: From Pearl Harbor to Hiroshima. Osprey Publishing. ISBN1-84176-882-0.