North Korea had six hydroelectric systems and six small thermoelectric plants at the outbreak of the war, and all were on the list of strategically important targets compiled by the Joint Chiefs of Staff (JCS). B-29 Superfortresses of the United States Air Force had begun bombing industrial targets in North Korea soon after the invasion of the South in the summer of 1950 but had not attacked any part of the power transmission grid. As early as August 23, 1950, while UN forces were still struggling to hold the Pusan Perimeter and well before the UN landing at Inchon, planners of the USAF FEAF (Far East Air Forces) had asked if the hydroelectric system should be attacked; no decision had yet been made as to whether North Korea was to be occupied.