The Yasuoka Detachment of Masaomi Yasuoka

Masanobu Tsuji (wikipedia)

On June 1939 the Kwantung Army planed an offensive against the Soviets on Nomonhan. Following the plans of  Major Masanobu Tsuji, Kwantung Army commanding General Kenkichi Ueda approved the deployment of reinforcements on the Nomonhan area. As part of these reinforcements, the Yasuoka Detachment was created.

The Yasuoka Detachment, a powerful strike force under command of Lieutenant General Masaomi Yasuoka, consisted on:

• 3rd Tank Regiment.
• 4th Tank Regiment.
• 26th Regiment of the IJA 23rd Infantry Division. 
• 28th Regiment of the IJA 7th Infantry Division. 
• 2nd Battalion of the 13th Field Artillery Regiment.
• 24th Independent Engineer Regiment.

The Yasuoka Detachment fielded 35 Type 95 Ha-Go light tanks, 38 medium tanks (4 Type 97 Chi-Ha and 34 Type 89 I-Go)  and 14 tankettes, and increased the Kwantung Army's presence in Nomonhan to 15.000 men and 120 artillery and antitank guns. On the other side, the Soviet force consisted on 12.500 men, 109 artillery and antitank guns, 186 tanks and 266 armored cars. Japanese armor was outnumbered by a 1:5 ratio.

Type 89 I-Go medium tank (pinterest).

Masaomi Yasuoka (Generals.dk)

Masaomi Yasuoka was born in 1886 and graduated from the Army Staff College in 1914. He served as Chief of Staff on different infantry brigades and was promoted to Colonel in 1930. He was subsequently promoted to Major General in 1935; and after being commander of the IJA 30th Infantry Brigade and Commandant of the Armor Warfare School, to Lieutenant General in 1938, when he was appointed commander of the IJA 1st Independent Mixed Brigade.

Due to his expertise in armored warfare, he was chosen to command the Yasuoka Detachment in Nomonhan. After being defeated by the Soviets and suffering heavy loses on the July 1939 offensive, the Detachment was dissolved and Yasuoka was send into the reserve and later retired from the army in 1941. 

In 1942, Masaomi Yasuoka became the military-governor of Surabaya (in Indonesia) until the Japanese surrender in August 1945. Yasuoka was then condemned to death for war crimes and hanged on April 1948. 

Sources:

- Nomonhan, 1939 The Red Army's Victory That Shaped WWII, Stuart D. Goldman.

- Wikipedia Yasuoka Detachment.

- Wikipedia Masaomi Yasuoka.

- Generals.dk

- The Pacific War Online Encyclopedia