Guerrilla warfare was outside this statement of scope, but such operations came under partial CIA control with NSC 10/5 of October 1951. See ""Psychological Strategy Board"" below. To implement covert actions under NSC 10/2, the OPC was created on September 1, 1948. Its initial structure had it taking guidance from the State Department in peacetime and from the military in wartime, initially had direct access to the State Department and to the military without having to proceed through the CIA's administrative hierarchy, provided the Director of Central Intelligence (DCI) was informed of all important projects and decisions. In 1950 this arrangement was modified to ensure that policy guidance came to OPC through the DCI. During the Korean War, the OPC grew quickly. Wartime commitments and other missions soon made covert action the most expensive and bureaucratically prominent of the CIA's activities.