He fought under three flags : Finnish , German ( when he fought the Soviets in World War II ) , and American ( where he was known as Larry Thorne ) when he served in U.S. Army Special Forces in the Vietnam War .
He is known as the soldier who fought under three flags : Finnish , German ( when he fought the Soviets in World War II ) , and American ( where he was known as Larry Thorne ) when he served in U.S. Army Special Forces ( Green Berets ) in the Vietnam War .