Two weeks into the war in Iraq, Marine Col. Joe D. Dowdy concluded the crowning military maneuver of his life, attacking an elite band of Iraqi troops and then shepherding 6,000 men on an 18-hour, high-speed race toward Baghdad.

But no praise awaited the First Marine regimental commander as he pushed into the tent of his superior, Maj. Gen. James Mattis, on April 4, 2003. Instead, Col. Dowdy was stripped of his command, which effectively ended his 24-year Marine career. In a final blow, Col. Dowdy says, the general asked him...