All Encompassing Intelligence - An Eye of Mordor On the Western Front

Modern day attention to information technology access by adversaries can look to the Great War for establishing the standard by which all activity was closely scrutinised through an array of intelligence collection.  Four years of war created incredible advances in weaponry and application to major operations involving millions of men.  Keeping pace with the advances was the ability to collect information and develop intelligence—particularly through the world of science and technology. The entire Western Front benefited from advances in intelligence collection, analysis, and dissemination.  Every adversary had access to a variety of sources from the electromagnetic spectrum, the physics of sound and light and from the third dimension employing the latest in aeronautical engineering and aeroplane design.  Information and intelligence had a primary purpose—described by Capitaine Jean De Bissy, an early French pioneer of aerial photographic interpretation, “to follow the destructive work of our Artillery and to register the victorious advance of our Infantry.” 

The top priority for Allied intelligence collection and analysis in 1918 was enumeration [ordered listing of all of the items in that collection] and position of enemy units, be it army corps, divisions, and regiments, facing the allied sector along the front line. At division-level the intelligence officer’s priority of information collection and analysis involved knowing the enemy infantry’s line of resistance, the number of effective troops in line constituting the order of battle, determining troop material and morale, ascertaining if reserves were being brought up, the strength of that support and when they could be brought into action. For regiments assigned to the front line, the regimental intelligence officer’s priority was to watch over the enemy defensive organisations and determine changes in observation posts, machine guns, shelters, and wire entanglements.  It was essential that the regimental intelligence officer kept his commander informed daily, “…and make him take an interest in it.”  It was a methodology that prioritised identity.  A British intelligence officer described a lucrative source:  “It may be stated that the most certain method of identifying the enemy’s units is by obtaining prisoners or deserters.  Next to this the best things are documents taken from dead or prisoners.” This was a well-established process for all combatants.  The Americans were novices, but relied on more experienced French 2^e Bureau intelligence to hone their interrogation skills.  As a senior British intelligence officer further reflected on the experience of acquiring information. “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.” What did not come with the new wave of intelligence and accessible information was operational solutions to break the deadlock that positional war created.

Gleaning German intentions for an attack took everything into consideration.  Trench raids (coup d’ main) became the standard for operations up and down the front line.  When information was needed for refining last minute operations, a trench raid was mounted to either capture prisoners for interrogation, gather available evidence from the enemy trenches, or both. The raiding party had priorities to make note of the trench construction, to include how the revetments were configured.  Any article of equipment was a source for intelligence analysis.  Captured booty such as helmets, caps, rifles, shoulder straps and identity discs complemented the analysis. Sources of information from prisoners and raids on enemy territory included orders, personal letters and correspondence, providing immediate importance to opposing units as well as unit identification. Critical to allied intelligence on German prisoners was the Soldbuchen or pay book.  It served as identification and contained the military record and provided discussion for the first interrogation.

Prisoner interrogation became a science of human emotion and psychology.  German military intelligence was aware that the allies had been told to expect beatings and other ordeals, and so ‘prisoners who, still feeling the violent emotions of battle, found themselves humanely treated….spoke more willingly even than the deserters.”  Allied interrogation centers took great care in ethnically separating German prisoners.  Polish and Alsace-Lorraine prisoners were kept in separate locations to promulgate their anger towards Germans, reinforced by better treatment and food “which nearly always loosens their tongues.”

Positional war meant continual observation of the enemy through a network of observation post stations strategically positioned along both sides of the front line. Ground observation’s incessant watch of the same enemy turf day after day acquired the fleeting opportunities that became valued intelligence.  Telescopes, periscopes and field glasses combined with panoramic ground-level photographs, pasted together to form a horizon line mosaic, provided detail for infantry analysis.   The panoramic mosaics were annotated with degrees marked so a consistent bearing to a recognised permanent point could be given for all observations.   Ground observation intelligence collection was not shared by all front line positions like sentries and machine gunners.  Their role required total concentration to react effectively against observed activity.  Instead, the ground observer was a highly experienced infantryman who could piece together an evolving situation and report in a timely manner back to intelligence elements or artillery units.

A private serving in the 26th Division in 1918 provided a testament to the environment. “Let me tell you of something we learned which proves that Fritz is no dub, even if he is a Hun.  It’s hard for the man on the front line watch during the night time to tell what’s going on out yonder in the shell-marked contested area.  He’s continually looking for something to develop.  Every possible precaution must be taken against raids or surprise attacks.  That’s why each side sends out men on listening duty to crawl around on their stomachs and get as close as possible to the opposite line to pick up any little scrap of conversation that might happen to float over the enemy’s parapet.  It’s a strict military order that there shall be no talking in the front line trenches, but soldiers under the long strain of the night will talk to each other now and then, generally in whispers or low overtone.  Sometimes listeners have brought back valuable bits of information foolishly dropped on the wings of the night by a nervous soldier who couldn’t restrain his tongue.  That is why each side sends up flares.  Always there is the hope of catching the other fellow in the act of spying.”

Sound ranging observation posts dotted both sides of No Man’s Land throughout the Western Front.  Sound Ranging used acoustical principles to locate enemy artillery.  Integral to the sound ranging operation was a forward observer who could recognise the artillery piece being fired by the sound created and phoned to headquarters any specifics regarding the weapon and location.  As the sonic wave traveled at the rate of 300 meters per second, it created an arc, which was measured by several stations emplaced along the front.  The time interval of the sound arc was measured and plotted on a map.  Sound ranging data was synthesised via a computer and the resulting information was passed on to the artillery via telephone. 

Complementing sound ranging of artillery fire throughout the Western Front was an extensive flash spotting network.  When an enemy battery opened fire, the flash spotting observer set his observation glass towards the flash and called his angle to the central station; these angles were laid off on the map at central, and where the lines subtending the angle from each observer crossed, there was the battery. The discharge of a high velocity gun was distinguishable from a howitzer by the sharp blade-like stab of flame emitted and the fact that little or no smoke was observed.  The flash of a howitzer on the other hand had a more deliberate appearance—a distinct yellowish color accompanied by a certain amount of smoke. So accurate was the system that a report was made every time an enemy battery fired the data was placed on a chart showing active and inactive locations of enemy batteries.  The absence of sound and light data prompted the artillery command posts to look elsewhere for targets.

Aviation on the Western Front was an essential component of intelligence.  Aeroplanes extended the visual range for analysis by corps and army planners and operators.  By virtue of their ability to cover a given area the two had similar missions of artillery direction, information gathering on enemy organisation and enemy works, monitoring front and rear echelons, and assisting long term analysis as it concerned combat sustainability through rail and road traffic.  The process was extensive throughout.  Products included “hasty drawings, sketches, and diagrams for the General Staff of the Division, study aeroplane photographs of enemy territory, to keep up to date the sector maps showing both Intelligence and Operations Information, to distribute maps, and to collect and forward to the Corps at prescribed intervals the corrections in trenches and other military features for incorporation in new editions of the battle map at Army Headquarters.”

Communication between aeroplane and division employed wireless radio, visual signals, signal rockets from the aeroplane, and written messages dropped from the aeroplane.  Ground communication to the aeroplane employed large panels, rockets, and Bengal flares. Communication between aviation and division was covered by long distance telephone lines maintained through regional exchanges.  In addition, pigeon lofts were set up at the airdrome to provide additional communications networks between the division and the Group.

Captive balloons were ideal for monitoring operations close to the front lines especially with telephonic connectivity to provide constant updates for ground commanders and artillery units.  The sector of surveillance for the balloon was the same as the zone of action for the artillery which it was supporting.  Divisional balloons supported division artillery fire with limited range.  Balloons attached to heavy artillery devoted their time to counter-battery work and the demolition of batteries recognised by their emplacements and works within the second position of the sector.  During an attack the divisional balloon followed the advance of the infantry, informing the commanders of the situation and disposition of the battle lines.  Enemy disposition and movements were also monitored.  During the battle aerostiers [and their German equivalent] watched enemy batteries that commenced fire and informed artillery of their locations for counter-battery.  Machine guns protected the balloons from enemy aviation.  The cardinal rule was they never took their eyes off their sector.

On the actual battleground, intelligence networks proliferated employing state of the art wiretapping techniques.  By 1915, communication networks at the front became obliterated thanks to incessant artillery, requiring ground telegraphy to provide communications within the trenches.  Electro-magnetic currents of comparatively low frequency could be detected directly by the telephone receiver. Wire-tapping units intercepted ground telegraph lines. Three kilometers was the normal range for transmissions, enough to support the average front line unit sector.  In turn, intercept stations working from the most forward trenches used the earth lines to listen in to the enemy telephone conversations in the opposite trenches.  Their intercept reporting provided indication of enemy relief and warning of imminent attacks. Conversations were intercepted either by induction through earth pickups or through actual wiretapping of the telephone lines that covered the front.  It was a testament to the bravery of both sides that many risked their lives to go into enemy lines and tap lines.  What resulted up and down the front line was conversations between all echelons became accessible by the enemy.  Attempts to counter this vulnerability resulted in the ultimate cryptographic development in the war—trench codes.

Spies within the units also added to the mystique of intelligence collection.  It was endemic, particularly when American forces arrived at the front lines.  An American officer from the 26^th Division recalled, “Spies inside our line evidently knew as much as we ourselves, for the relief was made under a very severe bombardment, all roads and trenches leading to the rear being heavily shelled practically all night long.  All the towns in the rear of the lines were infested by German spies.  Being so near the German frontier, and having for years intermarried, the natives who had been allowed to remain in their homes were in constant communication with the enemy.”  Another American officer reminded his troops, “The uniform is not a passport.”

Finally, when the Germans advanced into France and Belgium and set up their battle lines that became the longstanding Western Front, wherever possible they purposely chose the high ground offered through the available terrain. Positional war required constant surveillance to maintain advantage.  In the St. Mihiel sector, Cote 380 “Montsec” was the celebrated advance sentinel of hills facing the allies in the southern Woëvre front – a geographical high point that became the subject of legendary press dispatches. The Germans made Montsec one of the most lucrative observation posts on the Western Front providing continual observation until a month prior to the armistice.  Concrete underground observation stations overlooked every movement to the horizon.   Six galleries were constructed within the mountain with entrances facing the opposite northern reverse slope for extra-added protection from allied artillery fire.  Montsec internal galleries were located on the highest part of the ridge, configured with massive timbers, extended lighting and communication throughout using speaking tubes that connected each observation post.   The primary observation deck was configured to withstand any aerial or artillery attempts to blind the operation. Montsec governed the Woëvre battlefield not only in confirming the ultimate higher ground advantage but also a never-ending psychological dominance over the allied infantry. From Montsec the battleground spread like a map.  Every allied move for miles south of Seicheprey, to include the Beaumont Ridge, “Dead Man’s Curve,” and the towns to the south.  A better vantage point could not be imagined.   Soldiers in the Seicheprey area complained that they could not change a vermin-infested shirt without permission of the Germans.  Slogging each day in the eternal muck that was the trenches only added to the frustration and despair for each soldier because they saw a German adversary living high and dry.  On clear days, American soldiers were forbidden to walk on the roads, as the olive-drab uniform was easily detected from Montsec observatories on the white surface of the roads.  The only way to effectively reinforce ongoing operations was under cover of darkness or inclement weather with a very low cloud ceiling.  Likewise, Montsec effectually blocked American ground observation of gleaning German intentions for a potential attack. To maneuver everyday with movement open to enemy observation, to advance along roads accurately registered for enemy fire, and to conduct offensive operations without incident was miraculous at best.  Perhaps the most eloquent summation of aviation operations in the southern Woëvre region came from America’s leading ace Captain Eddie Rickenbacker’s post-war memoir that the high ground of Montsec dominated aviation’s role.  From the observation posts the Germans maintained constant surveillance of the airfields south of the front lines at Seicheprey.  “Not a machine could leave our field at Toul without being seen by these watchers atop Montsec!  No wonder their many photographing machines escaped us!  Many and many a time we had hurried out to the lines in answer to an alert, only to find that it was a false alarm.  Now we understood why we lost them.  The Germans had seen our coming, and by signaling their machines had given them warning in time to evade us.  They retired and landed and waited until we had returned home, then they calmly proceeded with their interrupted work!”  

For the Great War veteran J.R.R. Tolkein, author of Lord of the Rings, the standard by which all activity was closely scrutinised through an array of intelligence collection most likely served as the nightmare inspiration for the all-seeing eye of Sauron that insured evil ruled over all the land of Mordor and kept the enemies under constant surveillance.

Terrence J. Finnegan is a retired US Air Force Colonel and senior civil servant whose career spans four decades of military service. His career as a Military Intelligence professional covered analysis, production and planning at the US Department of Defense. He is the author of ‘A Delicate Affair’ on the Western Front: America Learns How to Fight a Modern War in the Woëvre Trenches (Spellmount, 2015). He is also the author of Shooting the Front: Allied Aerial Reconnaissance of the First World War (Spellmount, 2011).