Japanese tanks of World War II M4 Sherman medium tank. Originally, the next tank in development to replace the Type 1 Chi-He was the Type 4 Chi-To medium tank. However, the development of the Type 4 Chi-To was delayed, and a "stopgap tank" was needed. Development of the Chi-Nu started in May 1943 and was finished by October. The low priority given tanks, along with the raw material shortages meant that the Type 3 did not enter production until 1944. It was the last design based directly on Type 97 lineage. The Chi-Nu retained the same chassis and suspension of the Chi-He, but with a new
US signals intelligence in the Cold War evidence that a significant event was imminent, much less a North Korean invasion of the South. In 1952, when personnel levels and a more static war allowed some retrospective analysis, AFSA reviewed unprocessed intercept from the June 1950 period. Analysts could not find any message which would have given advance warning of the North Korean invasion. One of the earliest, if not the earliest, messages relating to the war, dated June 27 but not translated until October, referred to division level movement by North Korean forces. UN forces in the Korean War had an assortment of SIGINT units from the