had seen less fighting (or none) should have an opportunity to acquire experience in combat. In 1965, he deployed to Vietnam at the rank of Major, serving as an operations officer and battalion commander in the 101st Airborne Division. In November 1965, Hackworth founded a platoon-sized unit designated as Tiger Force to "out guerrilla the guerrillas". The unit carried out long-range reconnaissance patrol duties, suffering heavy casualties; it was eventually awarded the Presidential Unit Citation. However, after Hackworth was promoted out of Vietnam, the unit committed a series of war crimes, with U.S. Army investigative records estimating that Tiger Force soldiers killed hundreds of noncombatants. Hackworth later stated in an interview with the Toledo Blade that he was unaware of the war crimes the unit carried out and refused to speculate on why they occurred. Hackworth quickly developed a reputation as an eccentric but effective soldier, becoming a public figure in several books authored by General S. L. A. "Slam" Marshall. Following a stateside tour at the Pentagon and promotion to lieutenant colonel, Hackworth co-wrote The Vietnam Primer with Marshall after returning to Vietnam in the winter of 1966–67 on an Army-sponsored tour with the famous historian and commentator. The book advised counter-insurgency fighters to adopt some of the guerrilla tactics used by Mao Zedong, Che Guevara, and Ho Chi Minh. Hackworth described the strategy as "out-G-ing the G." His personal and professional relationship with Marshall soured as Hackworth became suspicious of his methods and motivation. However, both his assignment with "Slam" Marshall and his time on staff duty at the Pentagon soured Hackworth on the Vietnam War. One aspect of the latter required him to publicly defend the U.S. position on the war in a speaking tour. Even with his reservations concerning the conflict, he refused to resign, feeling it was his duty as a field grade officer to wage the campaign as best he could. Hackworth was assigned to a training battalion at Fort Lewis, Washington, and then returned to Vietnam to lead elements of the 9th Infantry Division, turning his theories about guerrilla warfare and how to counter it into practice with the 4th Battalion, 39th Infantry Regiment (4-39 Infantry) in the Mekong Delta, an underperforming unit made up largely of conscripts which Hackworth transformed into the counter-insurgent "Hardcore" Battalion (Recondo) from January to late May 1969. Hackworth next served as a senior military adviser to the