To correct the situation, General Selden cautioned his units to avoid unnecessary damage or destruction to the civilian economy. He directed his commanding officers to keep unauthorized Koreans away from Marine installations. Military police set up check points and instituted roving patrols to enforce division controls. Civil violators were turned over to Korean authorities or held for investigation before release. Civilians who lived in the forward areas were removed to the rear. They were prevented from going beyond STAYBACK until August 1952, when a controlled passage system was instituted. CHAPTER II Defending the Line _UN Command Activities--Defense of West and East Coast Korean Islands--Marine Air Operations--Spring 1952 on_ JAMESTOWN--_End of the Second Year of War--A Long Fourth of July--Changes in the Lineup--Replacement and Rotation--Logistical Operations, Summer 1952_ _UN Command Activities_[69] [69] Unless otherwise noted, the material in this section is derived from: Cdr Malcolm W. Cagle, USN and Cdr Frank A. Manson, USN, _The Sea War in Korea_ (Annapolis, Md.: U.S. Naval Institute, 1957), hereafter Cagle and Manson, _Sea War, Korea_; James A. Field, Jr., _History of United States Naval Operations_, Korea (Washington: [Div. of Naval Hist], 1962), hereafter Field, _NavOps, Korea_; John Miller, Jr., Maj Owen J. Carroll, USA, and Margaret E. Tackley, _Korea, 1951–1953_ (Washington: OCMH, DA, 1958), hereafter Miller, Carroll, and Tackley, _Korea, 1951–1953_. Movement of the 1st Marine Division to the west was part of an Eighth Army master plan to strengthen UN defenses and at the same time to enable South Korean forces to assume increased responsibility in the defense of their homeland. The tactical realignment in the spring of 1952 put more South Korean infantry units on the main line of resistance and buttressed the fighting front with five corps sectors instead of four. In the far west, the I Corps positions were newly manned (left to right) by the 1st Marine, 1st Commonwealth, 1st ROK, and the U.S. 45th Infantry Divisions. Next in line was IX Corps, whose left boundary General Van Fleet[70] had shifted further west, which now had a divisional line up of the ROK 9th on the left, the U.S. 7th in the center, and the U.S. 40th on the right. [70] General Van Fleet, CG, EUSAK since April 1951, had advocated a program in which South Korean troops would be rigorously trained to take over an increasingly greater part of the UNC defense efforts in Korea. See Mark W. Clark, _From the Danube to the Yalu_ (New York: Harper & Brothers, 1954), p. 185, hereafter Clark, _Danube to Yalu_, quoted with permission of the publishers.