The Kwantung Army staff officer whose Border Defense Guide sparked the Nomonhan Incident
After the war, General Ryukichi Tanaka testified that 'the most determined single protagonist in favor of war with the United States was Tsuji Masanobu.'
An operations staff officer of the Kwantung Army, Masanobu Tsuji drafted the 'Border Defense Guide' that touched off the 1939 Nomonhan Incident, pushing the border war with the Soviet Union forward by gekokujō, insubordination from below. After the defeat, his encounter with Soviet firepower turned him against war with the USSR, yet he became the most forceful advocate of war against the United States. A planner of the Malayan campaign and an instigator of the Bataan Death March and Sook Ching massacres, he evaded a war-crimes trial, returned to Japan, and was re-elected to the Diet.
Activities and affiliations
Career Timeline
- 1934Active in the Tōseiha (Control Faction), helped block the Kōdōha coup
- 1937–1939Kwantung Army operations staff officer
- 1939.04Authored the 'Border Defense Guide', instigating the Nomonhan Incident
- 1941General Staff Operations Section, advocate of war against the United States
- 1941–1942Planned the Malayan campaign; Sook Ching massacres after Singapore's fall
- 1942Bataan Death March; Guadalcanal offensive
- 1952Elected to the Diet (re-elected)
Related historical events
- 1938–1941The Soviet-Japanese Border Wars and the Neutrality PactKwantung Army staff officer who provoked the Nomonhan incidentHe provoked the incident through insubordination, and in 1941 cited Nomonhan fire-power as his reason not to attack the USSR.
- 1941–1945The Pacific WarJapanese campaign plannerHe planned the Malayan campaign and instigated the Sook Ching massacres.
Postwar hiding, US intelligence work, and disappearance in Laos
When the Japanese position in Burma collapsed in 1945, Masanobu Tsuji escaped, first to Thailand and then to China, where he renewed contacts made during his time in Nanking. He also visited Vietnam, then in disorder as the Viet Minh resisted the re-establishment of French rule. In China he was at once a prisoner and an employee of Chinese intelligence. Allowed to resign from Chinese service in 1948, he returned to Japan and began publishing books and articles on his war experiences; his account of hiding, Senko Sanzenri, became a bestseller. He was elected to the Diet in 1952 and won re-election, and in 1959 he became a member of the House of Councillors.
Cold War documents show that his political activity continued after the war. CIA files declassified in 2005–2006 state that Tsuji worked for American intelligence as a spy during the Cold War and was described as an 'inseparable pair' with Takushiro Hattori, who also worked with US intelligence. The files judged him valueless as an asset for lacking expertise in politics and information manipulation, yet portrayed him as the type of man who, given the chance, would start World War III without misgivings. They also contain an account that Hattori and Tsuji planned a 1952 coup, which Tsuji allegedly prevented by persuading the group that the real enemies were not conservatives like Yoshida but the Socialist Party. The files themselves state, however, that the CIA learned of the attempt only after the fact and that the information came from an unreliable source in China; some academics, including Tetsuo Arima of Waseda University, have suggested the whole story may have been a bluff leaked by Tsuji himself to appear more influential than he was.
In April 1961 Tsuji traveled to Laos and was never heard from again. It was thought he might have been killed in the Laotian Civil War, but there were also rumors that he became an advisor to the North Vietnamese government. The CIA files hold that, returning to Vientiane from Hanoi, he was kidnapped by the Chinese Communist Party and imprisoned in Yunnan; they considered him still alive as of 8 August 1962 on the basis of handwriting analysis of an envelope brought on 24 August 1962. He was never heard from again, and was declared dead on 20 July 1968. Where and how he died remains unconfirmed.