In October 1969, William Albracht, the youngest Green Beret captain in Vietnam, took command of a remote hilltop outpost called Fire Base Kate, held by only 27 American soldiers and 150 Montagnard militiamen. He found their defenses woefully unprepared. At dawn the next morning, three North Vietnamese Army regiments crossed the Cambodian border and attacked. Outnumbered three dozen to one, Albracht's men held off repeated ground assaults by communist...