Tactical Innovations and the American Experience
The Spring Offensives were not the first deployment of the AEF into the front, or its exposure to chemical weapons, that came in January. The key battles for the Americans in May and June occurred at Chateau-Thierry and Belleau Wood, well-known names in American military history, though frequently misunderstood. The first offensive operation by the AEF occurred at Cantigny in May when the 1st Infantry Division launched an attack in the sector. The Americans kept several translated German records of the units opposite the 1st Infantry Division in the battle. From those, it appears the Germans used chemical rounds in large numbers for lengthy barrages of French and American artillery in the sector. The German records suggest regular and constant chemical fire against artillery and rear areas by both their own artillery and from the Americans and French. Belleau Wood was a slaughterhouse of chemical casualties. The 2nd Infantry Division of the AEF, which included a Brigade of U.S. Marines, was under chemical attack for 31 of the 35 days it was engaged in the battle, despite a German order to economize their rapidly diminishing stockpile of chemical shell. By the end of the campaign, 32 percent of the Divisions casualties were from chemical agents.
Pershing and the AEF continually shortened training because of urgent need for fresh troops, especially by the summer as troop numbers increased and the AEF rushed to form an Army group for the Meuse-Argonne offensive. Units often entered the line with little to no experience and limited training. They also had serious equipment deficiencies, especially in gas masks. They suffered accordingly. For example, the 1st Army Corps of the AEF reported 4,190 casualties, 2262 from chemical weapons between March and mid-May 1918, during the German Spring Offensives. The officer preparing the report suggested this number of chemical casualties was artificially low, due to the relatively recent requirement to report gas casualties separately. In any case, it is safe to say over fifty percent of the casualties were due to chemical weapons. There were suggestions that the Germans singled out the Americans for “special treatment” in this regard, but the other Allies had only marginally better numbers in the same period. The Germans did like to take advantage of new troops in the line though. A preferred tactic was to hit new troops with irritants like sternators (sneezing powders) or tear gas for several weeks. This bred complacency and increased the efficiency of subsequent attacks with more deadly or dangerous agents.
The first into the line for the AEF was the 1st Infantry Division (ID), the only American division ever to complete the full schedule of training originally planned for all units of the AEF. The division saw limited action in Ansauville prior to the Spring Offensive, where the AEF suffered its first chemical attacks. Despite their training in chemical warfare, the 1st ID suffered a significant number of chemical casualties prior the Spring Offensive, even though deployed to a relatively quiet sector. Evaluation of the evidence suggests this was due to a lack of discipline and a tendency among troops to remove their masks without properly determining the all clear. Troops also developed the habit of switching to an unsafe French mask they carried as a backup because it was infinitely more comfortable than the standard issue British Small Box Respirator (SBR). Some troops also deployed into the line with defective American masks, these masks were only supposed to be used for training purposes, but recurring supply issues meant these were the only mask some troops ever got. Mask maintenance was an additional issue, as troops frequently failed protect and care for their masks. In part these problems stemmed from the AEF policy of robbing the 1st Division of trained officers, non-commissioned officers, and men to form cadre for units created from newly arrived and untrained troops and staff the AEF, Corps, and Army Headquarters. In theory, this leveled the training of the 1st Division across the AEF, in practicality it meant most troops in the AEF were untrained and led by individuals with only a few more months training than they possessed themselves. All of these issues were the pattern throughout the AEF during the war, though death rates fell as gas discipline improved with experience. This is part of the historical confusion about chemical warfare. Even as death rates plunged, casualty rates increased. Defensive measures like masks improved survivability, but the arrival of mustard agent changed the calculus, as the route of exposure was most often percutaneous, though not especially lethal.
While historical narratives usually sprint to the Armistice after the Spring Offense, starting with Amiens on August 8 and the 100 Days Offensive leading to a collapse of the German government and military opposition, the truth is more complicated. It was during these final months of the war that the chemical war took another critical turn. The Germans, shifting to defense, again innovated with chemical weapons. They adapted the area denial strategy used on the flanks of their previous offensive to the defense. Instead of their flanks, they used chemical weapons to their front against attacking forces. Chemical weapons became obstacles on the battlefield just like mines and barbed wire they could “channel” attacking forces and deny them the use of advantageous terrain. Mustard and chemical weapons were also useful in shielding a retreating force, allowing them to break contact speedily while pursuing forces donned protective gear and slowed to avoid contamination. The Allies quickly adopted the new German techniques and began to use their own chemical rounds in similar ways. This escalated the chemical war further. All aspects of military operations on both sides fully integrated chemical weapons in the offense and defense throughout the final months of the war. It was the wide use of German chemical weapons after the Spring Offensive that staved off their rapid defeat. Exhausted by not broken, the German Army continued to resist effectively for months. It was only in the final weeks of the war, as German artillery stockpiles and chemical agent dwindled, that the Allies met with significant offensive success.
The end of the war saw the AEF floundering in the Meuse-Argonne centered on the old battlefields of Verdun. If the end of the war began on August 8, someone forgot to tell the Germans in the Argonne. The largest American cemetery in Europe marks the toll they inflicted, most of it after August 8. American forces in the Meuse were under steady chemical attack while they struggled to execute large-scale operations with inexperienced troops and officers. The Germans, on the defensive, used mustard and other agents to great effect against the flailing Americans, even as the AEF attempted to incorporate chemical warfare into its own offensive operations.
On the offensive, the AEF was not always proficient in chemical warfare either. Using French supplied chemical shells fired from French supplied artillery; the AEF made use of gas to knock out machine gun points and suppress artillery, as well as deny terrain. At least they meant to. On several occasions where good use of chemical weapons might have saved countless American lives, either the artillery failed to provide it or commanders failed to request it. One of these occasions was the V Corps attack at Montfaucon on the 29 and 30 September. Under almost constant chemical attack, the shattered units of the 37th and 79th Divisions retired in chaos. Despite orders from First Army to use gas against the German artillery and machine gun emplacements then proving so devastating, the V Corps commander failed to comply out of either incompetence or a breakdown in communication between infantry and artillery that precluded it. Similar opportunities were gas might have made the infantry’s lot significantly easier existed at Belleau Wood and Chateau Thierry. Often these cases appear to be due to either supply issues, or the inexperience of commanders who did not even think to use gas.
Nevertheless, things improved. Describing one American attack in the Meuse Argonne, a post war writer noted, “just as the Germans seemed to be concentrating…eight of our big guns in a couple of hours coughed up twelve hundred tons of gas and spit it in the faces of an enemy that dared to think it could fool with Uncle Sam’s boys…” Hyperbolic statements aside, the account describes a tactic used by all the forces of the Western Front in 1918 – the use of chemical weapons to break up attacking forces by denying terrain, encumbering troops, and slowing their advance.
In 1918, the Historical Section of the AEF General Staff published a pamphlet evaluating German tactics based on intelligence and observation. The use of chemical warfare by German artillery came in for special attention, as did the fundamental shift of 1917-1918 in German chemical weapons especially in the Spring Offensives begun in March. The French took notice of the German tactics as well, and prescribed the use of gas in similar ways for their troops. The AEF followed suit. The AEF embraced chemical warfare, this is evident in both wartime directives and post war doctrine written in the immediate aftermath of the war, prior to the 1922 Washington Convention banning first use. Wartime directives became post war doctrine in 1919, published in the AEF Gas Manual, a six-part document. Following the first part on the tactical use of chemical weapons, the Gas Manual divided itself into parts based on the means of delivery: artillery, gas troops, infantry, and the air service. Each contained the specifics for achieving the tactical goals of the first part, with a final part describing defensive measures. It noted that chemical weapons were for both offensive and defensive operations. Offensively, chemical weapons were “for the purpose of assisting in gaining and maintaining that fire superiority necessary for the Infantry to advance,” while defensive use was to prevent the enemy from doing the same. In modern terms, chemical weapons shaped the battlefield - by denying terrain or limiting the movement of the enemy, attacking reserve and reinforcements limiting counter-attacks, encumbering enemy troops with protective equipment decreasing their mobility and accuracy of fire.
The tactical employment of gas was a fundamental component of post war doctrine. This runs counter to the entire traditional narrative. Chemical weapons provided significant tactical utility, hence the decision of the AEF to codify their use in doctrinal publications. Post-war war games and studies replicated these doctrinal changes, at least until 1922 and the Washington treaties. While debates raged after the war about the future of tanks and aircraft in military doctrine, there was little debate about how to use chemical weapons. The battlefield in 1918 settled it.
In our next post, we'll look at the inter-war period and answer the question "Why didn't the German's use chemical weapons in WWII?" The answer may surprise you.
 Paul B., Harm, tr., Cantigny Operation: Documents pertaining to German Raids (May 27, 1918) and American Attack and Capture of Cantigny (May 28, 1918): Selected Documents of: 18th army, XXVI Reserve Corps, 82d Reserve Division, 272 Reserve Inf. Regiment. (Washington, D.C: Army War College, 1931). The accuracy of the American translation cannot be accessed as some of the originals were in the Reichsarchiv, destroyed in World War II.
 Cochrane, US Army Chemical Corps Historical Studies, Gas Warfare in World War I, Gas Warfare at Belleau Wood, June 1918 (Washington, DC: U.S. Army Chemical Corps Historical Office, June 1957), 63-65. Cochrane cites archived reports of the 2nd Division and Lefebure. See also G.L. Spaulding and J.W. Wright, The Second Division, AEF, 1917-1919 (New York: Hillman Press, 1937), 60-65.
 Cochrane, Belleau Wood, 65-67. The 2nd Division took the most casualties of any AEF unit in the war over 137 days of combat. This was in part due to its reckless offensive spirit, and a lack of gas discipline among its troops. See also Cochrane, US Army Chemical Corps Historical Studies, Gas Warfare in World War I, Gas Warfare at Chateau Thierry, June 1918 (Washington DC: U.S. Army Chemical Corps Historical Office, July 1956).
 Cochrane, 79th at Mountfaucon, 94. See also Timothy K. Nenninger,“Tactical Dysfunction in the AEF,” Military Affairs, 51:4 (October) 1987, 177-181. Paul F. Braim, The Test of Battle: The American Expeditionary Forces in the Meuse-Argonne Campaign (University of Delaware Press, 1987). The French, British, and American leaders designated long training periods for the fresh troops of the AEF in 1917, shortly after the arrival of the AEF in Europe. Only the first four units deployed, which became the 1st Infantry Division, ever completed the entire training, and most of those soldiers that did, were reassigned to new units arriving as cadre or to AEF headquarters. The Allies were desperate for reinforcements during the German Spring Offensives and American units increasingly moved into the lines, with decreased training the result. By August of 1918, units were deploying almost straight to the front. Several units made up entirely of men and officers who had been civilians four months previous and only received limited basic training stateside, deployed into combat with disastrous results.
 Heller, 35-46; 61-65. See also Cochrane, Ansauville; and Jeffery K. Smart, History of the Army’s Protective Mask (Aberdeen Proving Ground, MD: U.S. Army Soldier and Biological Chemical Command, 2000)
 Rexmond Cochrane, Gas Warfare at Chateau-Thierry (Maryland: Chemical Warfare Service, 1956) 13; Cochrane quotes the original report.
 Historical Section, General Staff, American Expeditionary Forces, A Survey of German Tactics 1918, Tactical Studies, No. 1 (France: 29th Engineers, U.S. Army, 1918), 31. Fries and Cochrane also note this. Fries based on his experience, discusses it in “Gas in Attack,” “History” and Chemical Warfare. Cochrane regularly refers to this and similar “surprise tactics” throughout his various studies.
 Fries, “Gas in Attack and Gas in Defense”, “Gas in Defense,” 4-5; Fries, “History of the Chemical Warfare Service in France,” Combined Arms Research Library – Digital Library, March 19, 1919, http://cgsc.contentdm.oclc.org/utils/getdownloaditem/collection/p4013coll7/id/886/filename/887.pdf/mapsto/ pdf/type/singleitem (accessed 1 December 2014); and Cochrane, Ansauville. Fries notes the decision to equip troops with the M-2 was a bad one, but that the British SBR was almost unwearable, a common complaint throughout the AEF and British Forces. The SBR restricted airflow significantly via a hose placed in the mouth connected to a filter box on the chest. It required a nose clip to prevent inhaling gas through the nose. Over this assemblage was a loose mask cover whose goggles tended to fog up or get out of place restricting the view of the wearer. It was also impossible to speak while wearing the mask. Soldiers had to wear the mask, sometimes in excess of eight hours. The French M-2 was utterly useless for protection against all but a few gas cloud attacks, but was immensely more comfortable. Either troops exposed themselves switching from the SBR to the M-2, or they removed the SBR too soon, usually in order to escape the torture of wearing the awful thing.
 Jeffery K. Smart, History of the Army’s Protective Mask (Aberdeen Proving Ground, MD: U.S. Army Soldier and Biological Chemical Command, 2000). See also General Electric Company, The Story of the Development Division Chemical Warfare Service (Cleveland, OH: National Lamp Works, General Electric Company, 1920). Based on the accounts in Cochrane’s various studies, Heller’s own examination, and the primary source records and histories of several units of the AEF as well as the two sources cited, masks were in tight supply in the AEF and subject to “scrounging” and horse-trading as units prepared to enter the line. The French and British tested the American M-1 mask on behalf of the AEF and found it to be woefully inadequate. Heller has a complete account of the fiasco that produced it. Among other issues, the lenses in the mask had a tendency to fall out at random. By war’s end, the US had improved its supply, but the war ended before significant American equipment and weapons reached Europe. Based on the source evidence, it looks like the supply of masks, their serviceability, and compliance with AEF directives on masks varied widely. Consequently, owing to lack of supply, broken or lost equipment, or incompetence and lack of training, some troops entered the line with defective masks.
 This factor led to the interwar argument that chemical warfare was inherently more “humane” than conventional weapons. The development of nerve agents of both persistent and non-persistent varieties in the interwar era changed that calculus.
 Previous chemical weapons use was either in support of an offensive action or raid or as part of “harassing and interdiction” fires.
 Henry C. Thorn, Jr., The History of the 313th Infantry “Baltimore’s Own,” (New York: Wynkoop Hallenbeck Crawford Company, 1920), 35-36; Cochrane, 79th Division at Montfaucon, 37-40; Order of Battle of the United States Land Forces in the World War, America Expeditionary Forces: General Headquarters Armies, Army Corps, Services of Supply, Separate Forces, Vol. 1 (Washington, DC: Center of Military History United States Army, 1988), 291, 303-305.
 Ibid. Conclusions regarding the inaction are Cochrane’s.
 William Benjamin West, The Fight for the Argonne, Personal Experiences of a ‘Y’ Man (New York: Abingdon Press, 1919). West served in support of the AEF’s 37th Division as a member of the YMCA working in the rear. His hyperbole notwithstanding, the use of gas he describes was a normal tactic for both sides by the end of the war.
 Historical Section, General Staff, American Expeditionary Forces, “Chapter III – Artillery,” A Survey of German Tactics 1918, Tactical Studies, No. 1 (France: 29th Engineers, U.S. Army, 1918).
 U.S. Army Expeditionary Force, AEF No. 1475-1 G-5, Gas Manual, Part I – Tactical Employment of Gases (France: General Headquarters, AE, March 1919).
 Ibid, 20.