Retired Army officer Drew Dix and I met at the Infantry School at Fort Benning, Ga., in 1969. As former noncommissioned officers who had received direct commissions, we became acquainted while attending the Infantry Officer Basic Course. Staff Sergeant Dix earned the Medal of Honor (MOH) in Vietnam during the 1968 Tet Offensive, and President Lyndon Johnson had presented the medal to him in the White House shortly before we met. Dix tells his remarkable story in his book, “The Rescue of River City.” The former Special Forces soldier is one of the calmest men I’ve ever known, but he...