For conspicuous gallantry and intrepidity in action while serving with Company I, Third Battalion, Twenty-Seventh Marines, First Marine Division in support of operations against the enemy in the Republic of Vietnam. On 17 May 1968, while participating in Operation Allen Brook, Company I, while crossing a dry river bed, was ambushed by a heavily armed, well entrenched North Vietnamese enemy force. Company I took many casualties, including the commanding officer, all platoon leaders, and senior staff non-commissioned officers. Undaunted by the intensity of enemy fire, Sergeant Allison took command of the Marines around him and led them forward to a small bank. While the platoon made a stand and with total disregard of his own personal safety, he then made several trips across the fire-swept killing zone to retrieve water from a stream for the wounded and suffering. Sergeant Allison then continued to lead the surviving members in returning fire until the enemy was dislodged by Marine reinforcements. On 28 May 1968, while participating in Operation Allen Brook, Sergeant Allison's platoon, while approaching a tree line across open ground, was suddenly engaged by a well entrenched, heavily armed North Vietnamese enemy unit. Initial casualties were heavy. The surviving Marines continued to return fire. With a friendly tank knocked out, the remaining tanks fell back and platoon survivors were forced to find cover. When he saw two tanks advancing and recognizing that Marines were left behind in front of the tree line, Sergeant Allison, at grave personal risk, got behind one of the tanks and directed the tank's fire while they advanced towards the enemy held tree line. He then recovered two mortally wounded Marines and the few survivors were allowed to withdraw so that air strikes could be called in. By his bold initiative, undaunted courage, and complete dedication to duty, Sergeant Allison reflected great credit upon himself and upheld the highest traditions of the Marine Corps and the United States Naval Service.