In 1950, world tension increased as the divided country of Korea became the site of overt hostilities. "McNair" was soon taken out of mothballs, recommissioning 6 July 1951. Before the end of the year she had reported for duty in the Atlantic Fleet. On 6 September 1952, she departed her home port, Newport, R.I., for a world cruise that took her through the Panama Canal to Korea, where she served as gunfire support ship for United Nations troops and as guardian of carriers of the 7th Fleet. After 3 months in the combat area, she transited the Suez Canal en route home, arriving Newport 11 April 1953. In July she headed back across the Atlantic for a midshipman training cruise to northern Europe, followed by her first deployment with the 6th Fleet in the Mediterranean.