Editorial Note
On June 23, United Nations air and naval air forces bombed five North Korean hydroelectric plants, including the large generating plant at Sui-ho on the Yalu River, with additional strikes taking place over the next four days. For accounts of these air operations, see Hermes, Truce Tent and Fighting Front, pages 320–324; R. Frank Futrell, The United States Air Force in Korea 1950–1953, pages 451–453; James A. Field, Jr., History of United States Naval Operations: Korea, pages 4363–439; and Malcolm W. Cagel and Frank A. Manson, The Sea War in Korea, pages 441 ff.
Since July 1951 CINCUNC had discretionary authority to order these operations, except against the Sui-ho target. Regarding this authority, see paragraph 6 of the JCS directive to CINCUNC in telegram JCS 95977, July 10, 1951, printed in Foreign Relations, 1951, volume VII, Part 1, page 646. Five days before the attack the Joint Chiefs of Staff at the State–JCS meeting on June 18, had informed the State members in attendance that Clark was planning to bomb the hydroelectric plants in North Korea and had asked if State had any objection to including the plant on the Yalu River. Matthews and Nitze had replied probably not, but they would check with the Department of State. (State–JCS Meetings, lot 61 D 417)
On June 19, with the approval of the Department of State, the Secretary of Defense, and the President, the Joint Chiefs of Staff in telegram [Page 352] JCS 911683 advised Clark that restrictions on attacks against North Korean hydroelectric installations on the Yalu River were removed and he could initiate attacks. Clark was specifically advised that this authorization did not include authority to attack Manchuria or the territory of the Soviet Union, and as a matter of policy no operations would be conducted within 12 miles of Soviet territory on the Asiastic mainland. (795.00/6–1952 and Acheson, Present at the Creation, page 656)