Career pre-1942 Marshall enlisted in the
US Army on November 28, 1917, joining the
315th Engineer Battalion, part of the
90th Infantry Division. Based initially in Camp Travis, near
San Antonio,
Texas, his division transferred to
France with the
American Expeditionary Forces in June 1918 and Marshall was promoted to
sergeant. The 315th took part in the
Battle of Saint-Mihiel and
Meuse-Argonne Offensive. A 1921 history by of A Company 315th Engineers from formation to the end of 1918 shows that from 22 August to the Armistice, Marshall's company lost eight dead and fifteen wounded out of 165 men. Shortly after the
Armistice, Marshall was selected to take the entrance examinations for the
United States Military Academy, part of an initiative to promote exceptional soldiers from the ranks. He subsequently attended
Officer Candidate School, was commissioned in early 1919, and remained in France to assist with post-war demobilization. After his discharge, he remained in the
United States Army Reserve, and attended the Texas College of Mines, now the
University of Texas at El Paso. In the early 1920s, he became a newspaper reporter and editor, first with the
El Paso Herald, and later
The Detroit News. As a reporter, Marshall gained a national reputation for his coverage of Latin American and European military affairs, including the
Spanish Civil War. In 1940, he published
Blitzkrieg: Armies on Wheels, an analysis of the tactics developed by the
Wehrmacht prior to
World War II, and used during its invasion of
Poland and
Czechoslovakia.
World War II combat historian , a technique still employed by modern armies Following American entry into World War II in December 1941, the
United States Army created the "Center of Military History", whose role was to "gather historically significant data and materials" for the benefit of future historians, an organisation that still exists. This initially consisted of 27 officers, including Marshall, although he viewed himself as a military analyst, rather than a historian. His first combat assignment was the
Battle of Makin in November 1943, during which he used the
oral history technique known as
After action review, a process still employed by modern armies. He would gather surviving members of a front line unit and debrief them as a group on their combat experiences of a day or two before. Marshall later claimed he did so to resolve a dispute over who had been responsible for holding off a number of Japanese counter-attacks. By interviewing individual participants, each with a slightly different perspective, he created a considerably more detailed and accurate picture of the action than was possible previously. His experience as a journalist, and use of standard questions, allowed him to quickly produce large numbers of reports. These were used by the Army to identify tactical lessons; for example, Marshall found tanks called in to support infantry often withdrew even when their help was still required. To overcome this problem, they were made subordinate to the local infantry commander for the duration of the action. His interview techniques were quickly adopted throughout the US Army, and in 1944 Marshall was transferred to Europe where he ended the war as chief combat historian. In 1947, he used these interviews as the basis for his best known work
Men Against Fire, whose most notable conclusion was that 75% of individual riflemen engaged in combat never fired at an exposed enemy for the purpose of killing, even when directly threatened. Marshall argued civilian norms against taking life were so strong many conscripts could not bring themselves to kill, even at the risk of their own lives, and suggested changes in training that would increase the percentage willing to engage the enemy with direct fire. Many were incorporated by the US military; Marshall reported far more men fired weapons during the
Vietnam War. Less well known, but perhaps more significant, was a post-war project led by Marshall that employed former German officers to analyse all battles fought in Europe from 1939 to 1945. At its height, over 200 participated, including
Heinz Guderian and
Franz Halder, who allegedly used his position to vet the monographs and promulgate the
myth of the clean Wehrmacht.
Later military service Marshall was recalled for three months in late 1950 during the
Korean War as Historian/Operations Analyst for the
Eighth Army. He used numerous combat interviews with Americans serving in Korea to create a treatise titled "Commentary on Infantry and Weapons in Korea 1950–51". His conclusions were later incorporated into a plan to improve combat training, weapons, equipment, and tactics. Following his retirement from the Army Reserve in 1960, with the rank of brigadier general, Marshall continued to serve as an unofficial adviser. He was a member of the
Citizens Committee for a Free Cuba, founded in 1963. As a private citizen, he spent late 1966 and early 1967 in Vietnam on an Army-sponsored tour for the official purpose of teaching his after-action interview techniques to field commanders, in order to improve data collection for both the chain of command and the future official history of the Vietnam War. The Army Chief of Military History's representative on the tour, Colonel
David H. Hackworth, collected his own observations from the trip and published them as
The Vietnam Primer, with Marshall credited as co-author. ==Controversies==