Tanks of the United States US allies it was also used in conflicts beyond World War II. A 24-volt electrical system was used in the M4. Early Shermans mounted a 75 mm medium-velocity general-purpose gun. Although Ordnance began work on the Medium Tank T20 as a Sherman replacement, ultimately the Army decided to minimize production disruption by incorporating elements of other tank designs into the Sherman. Later M4A1, M4A2, and M4A3 models received the larger T23 turret with a high-velocity 76 mm M1 gun, which reduced the number of HE and smoke rounds carried and increased the number of anti-tank rounds. Later, the M4 and
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