Tanks of the United States John J. Pershing who led the American Expeditionary Force in Europe in World War I, it was designed and came out at the end of World War II and was used in the Korean Conflict. In May 1946, due to changing conceptions of the U.S. Army's tank needs, the M26 was reclassified as a medium tank. Designed as a heavy tank, the Pershing was a significant upgrade from the M4 Sherman in terms of firepower with its 90 mm gun and protection. On the other hand, its mobility was unsatisfactory for a medium tank (it used the same engine that
US signals intelligence in the Cold War continuing the World War II legacy. President Harry Truman, on 24 October 1952, issued a directive that set the stage for the National Security Agency, whose scope went beyond the pure military. NSA was created on 4 November 1952. Air Force SIGINT, by the Air Force Security Service, supported numerous Korean War operations. They often gave early warning of bombing attacks or ambushes for fighter aircraft. Since the North Koreans operated under Soviet doctrine, with strict ground control, the ground-controlled interception communications were especially vulnerable. North Korean orders to bombing units might well be intercepted and processed in the US