Answer:
President Truman removed General Douglas MacArthur, for MacArthur treated the Korean War as another World War, in which he had to destroy his opposition no matter the cost (it being the communist regime, and the weapon being nuclear weapons). Truman, on the other hand, knew of the delicate usage of the nuclear weapons, and if they are used, the USSR will counter. This led to Truman removing MacArthur for rash behavior.
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