on 23 August 1949 for 6th Fleet duty as flagship of Destroyer Squadron 18 (DESRON 18), returning on 27 January 1950. 1950–1960 With the advent of war in Korea, Joseph P. Kennedy Jr. carried out reserve training during July 1950, followed by bombardment and convoy exercises to prepare for action defending South Korea from Communist aggression. Joseph P. Kennedy Jr. sailed for Japan on 3 January 1951 by way of the Panama Canal, Pearl Harbor, and Midway Atoll. At Sasebo she loaded ammunition and, exactly one month after departure from Newport, joined Task Force 77 (TF 77) off Korea. From February to April she screened the attack carriers as they pounded enemy positions and supply lines. She departed on 8 April for the Formosa Patrol, helping to prevent further hostilities across the volatile Taiwan Straits. Joseph P. Kennedy Jr., then returned to Korea arriving off Wonsan on 20 May to take up bombardment station in support of the Allied siege and occupation of harbor islands. This duty continued until 13 June, a period of almost constant bombardment of great importance to the operation, after which the ship steamed to Sasebo. Joseph P. Kennedy Jr. did not return to the West Coast immediately upon the termination of this combat duty, but instead steamed westward to complete a circumnavigation of the globe. With other units of Destroyer Squadron 8, she visited Singapore, Bahrain, Port Said, Naples, and Gibraltar before returning to Newport on 9 August 1951. Until January 1953 she conducted battle practice and served as school ship for the Fleet Training School at Newport. She sailed on 7 January for another 6th Fleet cruise, returning to Newport on 18 May 1953. Antisubmarine training exercises and another Mediterranean cruise January – May 1954 comprised her duty through most of 1955, and she sailed on 5 November for Arctic maneuvers off northern Europe. The ship visited Oslo, Norway, and Bremerhaven, West Germany, carrying out tactical exercises with units of the 6th Fleet before returning to Newport on 5 March 1956. In June 1956, Joseph P. Kennedy Jr. arrived at Annapolis with battleships and to embark United States Naval Academy midshipmen for a training cruise. Upon returning from Northern Europe on 1 August, the ship took part in training operations until 6 May 1957, when she sailed once more for 6th Fleet duty. The Jordanian crisis had just passed with the strong support of