Sources of Frontline Intelligence: Prisoners of War & Repatriated Civilians

By Terrence J. Finnegan

German Prisoners: Future Sources of Intelligence

The Importance of the Order of Battle

To the military commander, knowing which unit was on the other side of No Man's Land—known as the order of battle—was the priority. A British intelligence officer commented that, "If reliable information is to be afforded by troops in the front line, it is essential that they should have some idea of the organization of the German army." A senior British analyst explained, "As everyone knows, the basis (of intelligence work) is the building up of the enemy's order of battle, for when this has been done the identification of one unit is prima facie evidence of the presence of the division to which it belongs and possible also of the corps or even army."

Prisoners

The most predominant source of intelligence collection in positional war was interrogation of prisoners. Both sides made capture and retention of prisoners a primary objective. Not only did it reduce the threat by one soldier, prisoners were usually a treasure trove of  information providing a sole source of information covering many critical issues. One British intelligence chief described the process. "Most of the information which a prisoner has is information in detail regarding the enemy defensive works on his own immediate front.

To extract this information from him requires time. It is sometimes necessary to take the prisoner back in the frontline trenches or to Observation Posts and almost always necessary to examine him with the assistance of aeroplane photographs." Ludendorff's chief spy manager at the front, Oberstleutnant Walter Nicolai, gave testament to the value of prisoner interrogations: "Our greatest and most valuable source of news in the western theatre of war—and at the frontline the only one—was furnished by prisoners of war."

Repatriated Men

Civilians in Newly Liberated Territory Had Lots of Information

An additional source of human intelligence consisted of interrogating repatriated civilians as they made it to Allied lines from German-held territory. Interviews were normally conducted by intelligence personnel in the sector looking for information on German activity and intentions. Following confirmation from local French authorities that the repatriated men were authentic, subsequent intelligence interviews sought elaboration on whatever modifications were being observed by aerial photography or other observation sources. 

Here's an example of valuable  information gathered from repatriated civilians by the AEF Intelligence Branch:

The 2 French civilians who came into our lines near Pont-a-Mousson on Sept 2, have described in detail a water supply system by which water from the Fontaine du Soiron, 66.8-48.3, is pumped to reservoirs at 3 points, each about 1 km. distant (N.W., S.W and S.) whence it is to be piped to points on the Hindenburg line from Dommartin, S.E. to Mont Plaisir Farm, for use in concrete work. This system is partly visible on photos, where it has the appearance of buried cable trenches, and it has been so represented on maps. The civilian's statement is entirely consistent with the photographic evidence and indicates that the further strengthening of the Hindenburg line is to be looked for at the points indicated. 

Source: "Summary of Intelligence," 1st Army Corps, U.S. Second Section, G.S. 

From "Military Intelligence at the Front," Over the Top, February 2009