For conspicuous gallantry and intrepidity in action at the risk of his life above and beyond the call of duty. 1st Lt. Thacker, Field Artillery, Battery A, distinguished himself while serving as the team leader of an Integrated Observation System collocated with elements of two Army of the Republic of Vietnam units at Fire Base 6. A numerically superior North Vietnamese Army force launched a well-planned dawn attack on the small, isolated, hilltop fire base. Employing rockets, grenades, flamethrowers, and automatic weapons, the enemy forces penetrated the perimeter defenses and engaged the defenders in hand-to-hand combat. Throughout the morning and early afternoon, 1st Lt. Thacker rallied and encouraged the U.S. and Republic of Vietnam soldiers in heroic efforts to repulse the enemy. He occupied a dangerously exposed observation position for a period of four hours while directing friendly air strikes and artillery fire against the assaulting enemy forces. His personal bravery and inspired leadership enabled the outnumbered friendly forces to inflict a maximum of casualties on the attacking enemy forces and prevented the base from being overrun. By late afternoon, the situation had become untenable. 1st Lt. Thacker organized and directed the withdrawal of the remaining friendly forces. With complete disregard for his personal safety, he remained inside the perimeter alone to provide covering fire with his M-16 rifle until all other friendly forces had escaped from the besieged fire base. Then, in an act of supreme courage, he called for friendly artillery fire on his own position to allow his comrades more time to withdraw safely from the area and, at the same time, inflict even greater casualties on the enemy forces. Although wounded and unable to escape from the area himself, he successfully eluded the enemy forces for eight days until friendly forces regained control of the fire base. The extraordinary courage and selflessness displayed by 1st Lt. Thacker were an inspiration to his comrades and are in the highest traditions of the military service.