For extraordinary heroism while serving as an Automatic Rifleman with company M, Third Battalion, Twenty-Seventh Marines, First Marine Division (Reinforced) in the Republic of Vietnam on 24 May 1968. While participating in Operation ALLEN BROOK in Quang Nam Province, Corporal Buchanan's company was serving as battalion reserve, following in trace of company K, as the unit rnoved against well-entrenched North Vietnamese forces in the village of Le Bac (1). Advancing into the objective area. Company K was ambushed by an enemy force in a tree line and two platoons were separated from the remainder of the company. As Corporal Buchanan's platoon quickly maneuvered toward the beleaguered Marines, it suddeniy came under intense small-arms and automatic weapons fire from a North Vietnamese Army unit entrenched in a series of bunkers and spider holes. In the initial burst of fire. several Marines were killed or seriously wounded, including the platoon commander, platoon sergeant, all the squad leaders and the radio operator. Observing a well-hidden enemy bunker, he fearlessly assaulted the position and directed accurate rifle fire into the emplacement. Then, retrieving the platoon radio and shouting to his comrades to follow, he led the Marines to the relative safety of a nearby pagoda where he established a hasty defense. Unable to establish radio communication with his company and upon observing several medical evacuation helicopters in the vicinity. he relayed a request for armed helicopter support. As he directed numerous air strikes on the enemy positions often within ten feet of his position, he courageously rushed into the fire-swept area to move the casualties to better protected positions. Upon discovering an adjacent bunker occupied by several North Vietnamese Army soldiers, Corporal Buchanan boldly assaulted it single- handedly, silencing the hostile fire. Throughout the intense three-hour battle, his superb command ability and calm presence of mind in hazardous situations undoubtedly saved numerous Marine lives and inspired all who observed him. By his outstanding leadership, intrepid fighting spirit and selfless devotion to duty, Corporal Buchanan upheld the highest traditions of the Marine Corps and the United States Naval Service.