Editing Western Front (World War I) (section)

== 1915 ==

[[File:Western front 1915-16.jpg|thumb|Map of the Western Front, 1915–16]]
Between the coast and the [[Vosges]] was a westward bulge in the trench line, named the Noyon salient after the French town at the maximum point of the German advance near [[Compiègne]]. Joffre's plan for 1915 was to attack the [[Salient (military)|salient]] on both flanks to cut it off.{{sfn|Fuller|1992|p=165}} The Fourth Army had attacked in Champagne from 20 December 1914&nbsp;– 17 March 1915 but the French were not able to attack in Artois at the same time. The [[10th Army (France)|Tenth Army]] formed the northern attack force and was to attack eastwards into the Douai plain on a {{cvt|16|km|adj=on}} front between Loos and Arras.{{sfn|Neiberg|2008|p=110}} On 10 March, as part of the larger offensive in the Artois region, the [[British Army]] fought the [[Battle of Neuve Chapelle]] to capture Aubers Ridge. The assault was made by four divisions on a {{cvt|2|mi|abbr=on}} front. Preceded by a hurricane bombardment lasting only 35 minutes, the village was captured within four hours. The advance then slowed because of supply and communication difficulties. The Germans brought up [[military reserves|reserves]] and [[counterattack]]ed, forestalling the attempt to capture the ridge. Since the British had used about a third of their [[shell (projectile)|artillery ammunition]], General Sir John French blamed the failure on the [[Shell Crisis of 1915]], despite the early success.{{sfn|Lyons|2000|p=112}}{{sfn|Fuller|1992|pp=166–7}}

=== Gas warfare ===

{{Main|Chemical weapons in World War I}}

All sides had signed the [[Hague Conventions of 1899 and 1907]], which prohibited the use of chemical weapons in warfare. In 1914, there had been small-scale attempts by both the French and Germans to use various [[tear gas]]es, which were not strictly prohibited by the early treaties but which were also ineffective.{{sfn|Richter|1994|p=7}} The first use of more lethal [[chemical weapon]]s on the Western Front was against the French near the Belgian town of [[Ypres]]. The Germans had already deployed gas against the Russians in the east at the [[Battle of Humin-Bolimów]].{{sfn|Doughty|2005|pp=148–151}}

[[File:The Second Battle of Ypres.jpg|thumb|left|An artist's rendition of Canadian troops at the [[Second Battle of Ypres]]]]
Despite the German plans to maintain the stalemate with the French and British, [[Albrecht, Duke of Württemberg]], commander of the [[4th Army (German Empire)|4th Army]] planned an offensive at Ypres, site of the First Battle of Ypres in November 1914. The [[Second Battle of Ypres]], April 1915, was intended to divert attention from offensives in the [[Eastern Front (World War I)|Eastern Front]] and disrupt Franco-British planning. After a two-day bombardment, the Germans released [[chemical weapons in World War I#1915: Large-scale use and lethal gases|a lethal cloud]] of {{convert|168|LT|t|abbr=on}} of [[chlorine]] onto the battlefield. Though primarily a powerful irritant, it can [[asphyxia]]te in high concentrations or prolonged exposure. Being heavier than air, the gas crept across [[no man's land#World War I|no man's land]] and drifted into the French trenches.{{sfn|Fuller|1992|pp=172–3}} The green-yellow cloud started killing some defenders and those in the rear fled in [[panic]], creating an undefended {{convert|6|km|mi|order=flip|adj=on}} gap in the entente line. The Germans were unprepared for the level of their success and lacked sufficient reserves to exploit the opening. Canadian troops on the right drew back their left flank and halted the German advance.{{sfn|Sheldon|2012|pp=81–95}} The gas attack was repeated two days later and caused a {{convert|5|km|mi|order=flip|abbr=on}} withdrawal of the Franco-British line but the opportunity had been lost.{{sfn|Sheldon|2012|pp=95–121}}

The success of this attack would not be repeated, as the entente countered by introducing gas masks and other [[countermeasure]]s. An example of the success of these measures came a year later, on 27 April in the [[Gas attacks at Hulluch]] {{convert|25|mi|km|order=flip|abbr=on}} to the south of Ypres, where the [[16th (Irish) Division]] withstood several German gas attacks.{{sfn|Jones|2002|pp=22–23}} The British retaliated, developing their own chlorine gas and using it at the [[Battle of Loos]] in September 1915. Fickle winds and inexperience led to more British casualties from the gas than German.{{sfn|Richter|1994|pp=69–73, 88}} French, British and German forces all escalated the use of gas attacks through the rest of the war, developing the more deadly [[phosgene]] gas in 1915, then the infamous [[mustard gas]] in 1917, which could linger for days and could kill slowly and painfully. Countermeasures also improved and the stalemate continued.{{sfn|Richter|1994|pp=182–183, 210–211}}

=== Air warfare ===
{{Main|Aviation in World War I}}
Specialised aeroplanes for aerial combat were introduced in 1915. Aircraft were already in use for scouting and on 1 April, the French pilot [[Roland Garros (aviator)|Roland Garros]] became the first to shoot down an enemy aircraft by using a machine-gun that shot forward through the propeller blades. This was achieved by crudely reinforcing the blades to deflect bullets.{{sfn|Spick|2002|pp=326–327}} Several weeks later Garros force-landed behind German lines. His aeroplane was captured and sent to Dutch engineer [[Anthony Fokker]], who soon produced a significant improvement, the [[synchronization gear|interrupter gear]], in which the machine gun is synchronised with the propeller so it fires in the intervals when the blades of the propeller are out of the line of fire. This advance was quickly ushered into service, in the [[Fokker E.I]] (''Eindecker'', or monoplane, Mark 1), the first single seat [[fighter aircraft]] to combine a reasonable maximum speed with an effective armament. [[Max Immelmann]] scored the first confirmed kill in an ''Eindecker'' on 1 August.{{sfn|Wise|1981|pp=349–350}} Both sides developed improved weapons, engines, airframes and materials, until the end of the war. It also inaugurated the cult of the [[flying ace|ace]], the most famous being [[Manfred von Richthofen]] (the Red Baron). Contrary to the myth, [[Antiaircraft warfare|anti-aircraft fire]] claimed more kills than fighters.{{sfn|Granatstein|Morton|2003|p=40}}

=== Spring offensive ===

[[File:Capture of Carency aftermath 1915 1.jpg|thumb|Ruins of [[Carency]] after it was recaptured by France]]
The final entente offensive of the spring was the [[Second Battle of Artois]], an offensive to capture Vimy Ridge and advance into the Douai plain. The French Tenth Army attacked on 9 May after a six-day bombardment and advanced {{convert|3|mi|km|order=flip|0}} to capture Vimy Ridge. German reinforcements counter-attacked and pushed the French back towards their starting points because French reserves had been held back and the success of the attack had come as a surprise. By 15 May the advance had been stopped, although the fighting continued until 18 June.{{sfn|Smith|Audoin-Rouzeau|Becker|2003|pp=79–80}} In May the German Army captured a French document at [[La Ville-aux-Bois]] describing a new system of defence. Rather than relying on a heavily fortified front line, the defence was to be arranged in a series of echelons. The front line would be a thinly manned series of outposts, reinforced by a series of strongpoints and a sheltered reserve. If a slope was available, troops were deployed along the rear side for protection. The defence became fully integrated with command of artillery at the divisional level. Members of the German high command viewed this new scheme with some favour and it later became the basis of an elastic [[defence in depth]] doctrine against entente attacks.{{sfn|Herwig|1997|p=165}}{{sfn|Lupfer|1981|pp=1–36}}

During the autumn of 1915, the "[[Fokker Scourge]]" began to have an effect on the battlefront as entente reconnaissance aircraft were nearly driven from the skies. These [[reconnaissance aircraft]] were used to direct gunnery and photograph enemy fortifications but now the entente were nearly blinded by German fighters.{{sfn|Campbell|1981|pp=26–27}} However, the impact of German air superiority was diminished by their primarily defensive doctrine in which they tended to remain over their own lines, rather than fighting over entente held territory.{{sfn|Griffith|1994|pp=155–156}}

=== Autumn offensive ===

In September 1915 the entente launched another offensive, with the French [[Third Battle of Artois]], [[Second Battle of Champagne]] and the British at Loos. The French had spent the summer preparing for this action, with the British assuming control of more of the front to release French troops for the attack. The bombardment, which had been carefully targeted by means of [[aerial photography]],{{sfn|Bailey|2004|p=245}} began on 22 September. The main French assault was launched on 25 September and, at first, made good progress in spite of surviving wire entanglements and machine gun posts. Rather than retreating, the Germans adopted a new [[defence-in-depth]] scheme that consisted of a series of defensive zones and positions with a depth of up to {{convert|5|mi|km|abbr=on|order=flip}}.{{sfn|Samuels|1995|pp=168–171}}

On 25 September, the British began the [[Battle of Loos]], part of the Third Battle of Artois, which was meant to supplement the larger Champagne attack. The attack was preceded by a four-day artillery bombardment of 250,000 shells and a release of 5,100 cylinders of chlorine gas.{{sfn|Palazzo|2000|p=66}}{{sfn|Hartesveldt|2005|p=17}} The attack involved two corps in the main assault and two corps performing diversionary attacks at Ypres. The British suffered heavy losses, especially due to machine gun fire during the attack and made only limited gains before they ran out of shells. A renewal of the attack on 13 October fared little better.{{sfn|Warner|2000|pp=4–31}} In December, French was replaced by General [[Douglas Haig, 1st Earl Haig|Douglas Haig]] as commander of the British forces.{{sfn|Wiest|2005|p=xvii}}