Nolan becomes Army’s first G2 (Intelligence) officer
May 28, 1917
When Gen. John Pershing took command of the American Expeditionary Forces, or AEF, in June 1917, his entire combat force consisted of a small headquarters and a division of infantry troops, with no staff organization or intelligence assets. Seventeen months later, the AEF had grown into a force of 29 combat divisions. Pershing’s staff section included a full-fledged theater intelligence center engaged in a wider range of intelligence activities than anywhere else in the United States military.
Once in Europe, Pershing decided to adopt the French staff system throughout the AEF: Administrative (G-1), Intelligence (G-2), Operations (G-3), Logistics (G-4) and Training (G-5).
Pershing selected Maj. Dennis Nolan, with whom he had served in Mexico, as the head of his G-2 section. Nolan moved into his first headquarters in Paris, sharing an office with his entire staff section – two officers and two clerks – and immediately set out to study how the French and British armies structured their intelligence sections. He then proceeded to build the AEF G-2 from scratch. The General Staff organization was repeated in tactical units down to the battalion level. Each level, therefore, had its own intelligence staff and organic intelligence assets, and the intelligence officers at each echelon were expected to look at progressively further distances behind enemy lines.
When Nolan took over as head of the Intelligence Section on May 28, 1917, he became the Army’s first G-2. Nolan organized the G-2 Section following the British example, dividing duties amongst four principal divisions: Information, Secret Service, Topographical, and the Censorship and Press Divisions. This structure was an overlapping and mutually supporting intelligence system that stretched from the AEF Headquarters in Chaumont, France, to the front lines of the war.
In addition to the traditional methods of intelligence collection: patrolling, observation, prisoner interrogation and document translation, Nolan added aerial observation, aerial photography and radio intelligence. Nolan also initiated the Corps of Intelligence Police, or CIP, a group of 50 enlisted specialists who spoke French fluently and had experience in investigative work. The CIP, which would eventually become the Counter Intelligence Corps in 1942, was a permanent counterintelligence organization that outlived the war into peacetime.
Many of the soldiers who were assigned to the AEF’s intelligence teams did not have formal intelligence training. The AEF had to improvise; they started an intelligence school at Langres, France, in 1918. Interrogation and Document Exploitation were taught at this school.
Nolan’s G-2 organization was the largest to date, incorporating a number of modern disciplines and intelligence functions for the first time: Acoustic Intelligence, Communications Security, Photo Intelligence, Signals Intelligence and Counter Intelligence.
By the time Germany signed the Armistice on Nov. 11, 1918, the AEF had evolved into a modern, combat-tested army recognized as one of the best in the world. The efficiency of the intelligence service helped contribute to the American Army’s success, and Nolan was awarded the Distinguished Service Medal “for organizing and administering the A.E.F. intelligence service.”