"My dear General Pershing: I hear from everywhere, and especially from the armies and civil authorities of the east, that, in their generous enthusiasm on account of the prospect of a great success over the enemy, numerous American officers and soldiers have talked in a public way of the projects of the High Command in the Woëvre. …It is impossible that the enemy should not be forewarned…." --Gen. Henri Philippe Pétain, Commander-in-Chief, French Army
The date was Aug. 19, 1918. After 15 months of preparation, planning and training, the American Expeditionary Forces (AEF) was finally ready to launch its first large-scale military operation of World War I. The early September offensive would pit the U.S. First Army and more than 100,000 French troops against 11 German divisions at the St. Mihiel salient in northeastern France. The French were worried, and rightly so. Inexperienced American Soldiers and officers, who certainly should have known better, were egregiously violating operational security.
Gen. John J. Pershing, commander of the AEF, was no stranger to the importance of negative intelligence--keeping information from the enemy. Chagrined that his own troops were exhibiting such carelessness, Pershing replied to Pétain on Aug. 22, 1918: "…the importance of the considerations which you have set forth relative to the necessity for secrecy in all operations had not escaped me. I keenly regret that indiscretions may have been committed, and I consider, with you, that we must attempt to deceive the enemy upon the actual directions the attack."
Pershing directed the Information Division within his G-2 Section to devise and execute, in very short order, a plan to mislead the Germans as to the true location of the planned American attack. The chief of the division was Capt. (later Col.) Arthur L. Conger, Jr., a Harvard graduate, instructor at Fort Leavenworth, Kansas, and German linguist familiar with the German army.
Conger, however, was a reluctant intelligence officer. Reportedly difficult to work with, he had been passed over by other AEF staff officers and ended up "stuck" in the G-2. After the war, Conger told a group of new intelligence officers, "I was one of those people in Intelligence who felt that they were in the wrong place all during the war and wanted very much to be some place else." Despite his wishes, Conger was second in command to Maj. (later Maj. Gen.) Dennis Nolan, the AEF G-2.
Although unhappy about the assignment, Conger attacked it with vigor. To prevent further security breaches, he limited knowledge of the deception plan to Pershing, his Chief of Staff, and the AEF G-3. Conger had the G-3 issue a confidential order to the VI Corps commander to establish a headquarters at Belfort and to expect seven divisions for an attack on the city of Mulhouse through the Belfort Gap, 125 miles southeast of St. Mihiel. Staff officers from the corps and each of the named divisions converged on Belfort to arrange for lodging and administrative space to support this large force.
Conger also traveled to Belfort, a hot bed of German sympathizers and spies, where he dropped hints to local inhabitants and conveniently left "confidential" papers in plain sight. He arranged for reconnaissance flights over enemy lines, sent borrowed French tanks to drive around open fields, and dispatched agents to scout rail lines, roads and hospital facilities. Signal units set up large antennas and proceeded to dispatch a flurry of messages.
Throughout the execution of his deception plan, Conger expressed pessimism on its chances for success, doubting "that the enemy takes this reconnaissance very seriously; … [he won't] be deceived by a mere 'paperwork' demonstration or reconnaissance of officers, unaccompanied by actual preparations of guns, munitions, materiel, and subsistence…." And he was right. German intelligence officers doubted the legitimacy of the information they received out of Belfort but felt it was too important to ignore completely. After all, Belfort might very well have been the true site of the upcoming attack and the American preparations at St. Mihiel the ruse.
Ultimately, the Belfort Ruse had little impact on the offensive at St. Mihiel. It did sow enough confusion and concern within the German forces for them to divert resources, time and effort that could have been more effective elsewhere. Pershing believed the ruse successful enough to request additional deception operations to keep the enemy uncertain and distracted.
After the war, Conger stated, "Of course, it is as old as the history of war for false information to be given to the enemy." Indeed, examples, both successful and not, can be found throughout U.S. Army history. Used to counteract a serious security leak or to mislead the enemy, deception operations can help a commander preserve that all-important principle of war--security.