While the Western Front had reached stalemate, the war continued in East Europe. Initial Russian plans called for simultaneous invasions of Austrian Galicia and German East Prussia. Although Russia's initial advance into Galicia was largely successful, it was driven back from East Prussia by Hindenburg and Ludendorff at Tannenberg and the Masurian Lakes in August and September 1914. Russia's less developed industrial base and ineffective military leadership was instrumental in the events that unfolded. By the spring of 1915, the Russians had retreated to Galicia, and, in May, the Central Powers achieved a remarkable breakthrough on Poland's southern frontiers. On 5 August, they captured Warsaw and forced the Russians to withdraw from Poland.
Despite the success of the June 1916 Brusilov Offensive in eastern Galicia, dissatisfaction with the Russian government's conduct of the war grew. The offensive's success was undermined by the reluctance of other generals to commit their forces to support the victory. Allied and Russian forces were revived only temporarily by Romania's entry into the war on 27 August. German forces came to the aid of embattled Austro-Hungarian units in Transylvania while a German-Bulgarian force attacked from the south, and Bucharest fell to the Central Powers on 6 December. Meanwhile, unrest grew in Russia, as the Tsar remained at the front. Empress Alexandra's increasingly incompetent rule drew protests and resulted in the murder of her favourite, Rasputin, at the end of 1916.
In March 1917, demonstrations in Petrograd culminated in the abdication of Tsar Nicholas II and the appointment of a weak Provisional Government, which shared power with the Petrograd Soviet socialists. This arrangement led to confusion and chaos both at the front and at home. The army became increasingly ineffective.
Discontent and the weaknesses of the Provisional Government led to a rise in the popularity of the Bolshevik Party, led by Vladimir Lenin, which demanded an immediate end to the war. The successful armed uprising by the Bolsheviks of November was followed in December by an armistice and negotiations with Germany. At first, the Bolsheviks refused the German terms, but when German troops began marching across the Ukraine unopposed, the new government acceded to the Treaty of Brest-Litovsk on 3 March 1918. The treaty ceded vast territories, including Finland, the Baltic provinces, parts of Poland and Ukraine to the Central Powers. Despite this enormous apparent German success, the manpower required for German occupation of former Russian territory may have contributed to the failure of the Spring Offensive and secured relatively little food or other materiel.
With the adoption of the Treaty of Brest-Litovsk, the Entente no longer existed. The Allied powers led a small-scale invasion of Russia, partly to stop Germany from exploiting Russian resources and, to a lesser extent, to support the "Whites" (as opposed to the "Reds") in the Russian Civil War. Allied troops landed in Arkhangelsk and in Vladivostok as part of the North Russia Intervention.
The Czechoslovak Legion fought together with the Entente—their goal was to win support for the independence of Czechoslovakia. The Legion in Russia was established in 1917, in December 1917 in France (including volunteers from America) and in April 1918 in Italy. Czechoslovak Legion troops defeated the Austro-Hungarian army at the Ukrainian village Zborov in July 1917. After this success, the number of Czechoslovak legionaries increased, as well as Czechoslovak military power. In the battle of Bakhmach, the Legion defeated the Germans and forced them to make a truce.
In Russia, they were heavily involved in the Russian Civil War fighting the Bolsheviks, at times controlling most of the Trans-Siberian railway and conquering all major cities in Siberia. The presence of the Czechoslovak Legion near the Yekaterinburg appears to have been one of the motivating forces for the Bolshevik execution of the Tsar and his family in July 1918. Legionaries came less than a week afterwards and captured the city.
Because Russia's European ports were not safe, the corps was to be evacuated by a long detour via the port of Vladivostok. The last transport was the American ship Heffron in September 1920.
Central Powers proposal for starting peace negotiations
Developments in 1917
The British naval blockade began to have a serious impact on Germany. In response, in February 1917, the German General Staff convinced Chancellor Theobald von Bethmann-Hollweg to declare unrestricted submarine warfare, with the goal of starving Britain out of the war. German planners estimated that unrestricted submarine warfare would cost Britain a monthly shipping loss of 600,000 tons. The General Staff acknowledged that the policy would almost certainly bring the United States into the conflict, but calculated that British shipping losses would be so high that they would be forced to sue for peace after 5 to 6 months, before American intervention could make an impact. In reality, tonnage sunk rose above 500,000 tons per month from February to July. It peaked at 860,000 tons in April. After July, the newly re-introduced convoy system became extremely effective in reducing the U-boat threat. Britain was safe from starvation, while German industrial output fell and the United States troops joined the war in large numbers far earlier than Germany had anticipated.
On 3 May 1917, during the Nivelle Offensive, the weary French 2nd Colonial Division, veterans of the Battle of Verdun, refused their orders, arriving drunk and without their weapons. Their officers lacked the means to punish an entire division, and harsh measures were not immediately implemented. Then, the French Army Mutinies afflicted an additional 54 French divisions and saw 20,000 men desert. The other Allied forces attacked, but sustained tremendous casualties. However, appeals to patriotism and duty, as well as mass arrests and trials, encouraged the soldiers to return to defend their trenches, although the French soldiers refused to participate in further offensive action. Robert Nivelle was removed from command by 15 May, replaced by General Philippe Pétain, who suspended bloody large-scale attacks.
The victory of Austria-Hungary and Germany at the Battle of Caporetto led the Allies to convene the Rapallo Conference at which they formed the Supreme War Council to coordinate planning. Previously, British and French armies had operated under separate commands.
In December, the Central Powers signed an armistice with Russia. This released large numbers of German troops for use in the west. With German reinforcements and new American troops pouring in, the outcome was to be decided on the Western Front. The Central Powers knew that they could not win a protracted war, but they held high hopes for success based on a final quick offensive. Furthermore, the leaders of the Central Powers and the Allies became increasingly fearful of social unrest and revolution in Europe. Thus, both sides urgently sought a decisive victory.
In 1917, Emperor Charles I of Austria secretly attempted separate peace negotiations with Clemenceau, with his wife's brother Sixtus in Belgium as an intermediary, without the knowledge of Germany. Italy opposed the proposals. When the negotiations failed, his attempt was revealed to Germany, resulting in a diplomatic catastrophe.
Ottoman Empire conflict, 1917–1918
In March and April 1917, at the First and Second Battles of Gaza, German and Ottoman forces stopped the advance of the Egyptian Expeditionary Force, which had begun in August 1916 at Romania. At the end of October, the Sinai and Palestine Campaign resumed, when General Edmund Allenby's XXth Corps, XXI Corps and Desert Mounted Corps won the Battle of Beersheba. Two Ottoman armies were defeated a few weeks later at the Battle of Mughar Ridge and, early in December, Jerusalem was captured following another Ottoman defeat at the Battle of Jerusalem (1917). About this time, Friedrich Freiherr Kress von Kressenstein was relieved of his duties as the Eighth Army's commander, replaced by Djevad Pasha, and a few months later the commander of the Ottoman Army in Palestine, Erich von Falkenhayn, was replaced by Otto Liman von Sanders.
Early in 1918, the front line was extended into the Jordan Valley, which continued to be occupied, following the First Transjordan and the Second Transjordan attack by British Empire forces in March and April 1918, into the summer. During March, most of the Egyptian Expeditionary Force's British infantry and Yeomanry cavalry were sent to fight on the Western Front as a consequence of the Spring Offensive. They were replaced by Indian Army units. During several months of reorganisation and training during the summer, a number of attacks were carried out on sections of the Ottoman front line. These pushed the front line north to more advantageous positions in preparation for an attack and to acclimatise the newly arrived Indian Army infantry. It was not until the middle of September that the integrated force was ready for large-scale operations.
The reorganised Egyptian Expeditionary Force, with an additional mounted division, broke Ottoman forces at the Battle of Megiddo in September 1918. In two days the British and Indian infantry supported by a creeping barrage broke the Ottoman front line and captured the headquarters of the Eighth Army (Ottoman Empire) at Tulkarm, the continuous trench lines at Tabsor, Arara and the Seventh Army (Ottoman Empire) headquarters at Nablus. The Desert Mounted Corps rode through the break in the front line created by the infantry and, during virtually continuous operations by Australian Light Horse, British mounted Yeomanry, Indian Lancers and New Zealand Mounted Rifle brigades in the Jezreel Valley, they captured Nazareth, Afulah and Beisan, Jenin, along with Haifa on the Mediterranean coast and Daraa east of the Jordan River on the Hejaz railway. Samakh and Tiberias on the Sea of Galilee, were captured on the way northwards to Damascus. Meanwhile, Chaytor's Force of Australian light horse, New Zealand mounted rifles, Indian, British West Indies and Jewish infantry captured the crossings of the Jordan River, Es Salt, Amman and at Ziza most of the Fourth Army (Ottoman Empire). The Armistice of Mudros, signed at the end of October ended hostilities with the Ottoman Empire when fighting was continuing north of Aleppo.
Entry of the United States
President Wilson before Congress, announcing the break in official relations with Germany on 3 February 1917.
At the outbreak of the war, the United States pursued a policy of non-intervention, avoiding conflict while trying to broker a peace. When a German U-boat sank the British liner RMS Lusitania on 7 May 1915 with 128 Americans among the dead, President Woodrow Wilson insisted that "America is too proud to fight" but demanded an end to attacks on passenger ships. Germany complied. Wilson unsuccessfully tried to mediate a settlement. However, he also repeatedly warned that the United States would not tolerate unrestricted submarine warfare, in violation of international law. The former president Theodore Roosevelt denounced German acts as "piracy". Wilson was narrowly reelected in 1916 as his supporters emphasized "he kept us out of war".
In January 1917, Germany resumed unrestricted submarine warfare, realizing it would mean American entry. The German Foreign Minister, in the Zimmermann Telegram, invited Mexico to join the war as Germany's ally against the United States. In return, the Germans would finance Mexico's war and help it recover the territories of Texas, New Mexico, and Arizona. The United Kingdom intercepted the message and presented it to the US embassy in the UK. From there it made its way to President Wilson who released the Zimmerman note to the public, and Americans saw it as casus belli—a cause for war. Wilson called on antiwar elements to end all wars, by winning this one and eliminating militarism from the globe. He argued that the war was so important that the US had to have a voice in the peace conference. After the sinking of seven US merchant ships by submarines and the publication of the Zimmerman telegram, Wilson called for war on Germany, which the US Congress declared on 6 April 1917.
The United States was never formally a member of the Allies but became a self-styled "Associated Power". The United States had a small army, but, after the passage of the Selective Service Act, it drafted 2.8 million men, and, by summer 1918, was sending 10,000 fresh soldiers to France every day. In 1917, the US Congress gave US citizenship to Puerto Ricans when they were drafted to participate in World War I, as part of the Jones Act. Germany had miscalculated, believing it would be many more months before American soldiers would arrive and that their arrival could be stopped by U-boats.
The United States Navy sent a battleship group to Scapa Flow to join with the British Grand Fleet, destroyers to Queenstown, Ireland, and submarines to help guard convoys. Several regiments of US Marines were also dispatched to France. The British and French wanted American units used to reinforce their troops already on the battle lines and not waste scarce shipping on bringing over supplies. General John J. Pershing, American Expeditionary Forces (AEF) commander, refused to break up American units to be used as reinforcements for British Empire and French units. As an exception, he did allow African-American combat regiments to be used in French divisions. The Harlem Hellfighters fought as part of the French 16th Division, earning a unit Croix de Guerre for their actions at Château-Thierry, Belleau Wood, and Sechault. AEF doctrine called for the use of frontal assaults, which had long since been discarded by British Empire and French commanders because of the large loss of life.
German Spring Offensive of 1918
French soldiers under General Gouraud, with machine guns amongst the ruins of a cathedral near the Marne, 1918.
German General Erich Ludendorff drew up plans (codenamed Operation Michael) for the 1918 offensive on the Western Front. The Spring Offensive sought to divide the British and French forces with a series of feints and advances. The German leadership hoped to end the war before significant US forces arrived. The operation commenced on 21 March 1918, with an attack on British forces near Amiens. German forces achieved an unprecedented advance of 60 kilometres (37 mi).
British and French trenches were penetrated using novel infiltration tactics, also named Hutier tactics, after General Oskar von Hutier, by specially trained units called Stosstruppen. Previously, attacks had been characterised by long artillery bombardments and massed assaults. However, in the Spring Offensive of 1918, Ludendorff used artillery only briefly and infiltrated small groups of infantry at weak points. They attacked command and logistics areas and bypassed points of serious resistance. More heavily armed infantry then destroyed these isolated positions. German success relied greatly on the element of surprise.
The front moved to within 120 kilometres (75 mi) of Paris. Three heavy Krupp railway guns fired 183 shells on the capital, causing many Parisians to flee. The initial offensive was so successful that Kaiser Wilhelm II declared 24 March a national holiday. Many Germans thought victory was near. After heavy fighting, however, the offensive was halted. Lacking tanks or motorised artillery, the Germans were unable to consolidate their gains. This situation was not helped by the supply lines now being stretched as a result of their rapid advance over devastated ground.
General Foch pressed to use the arriving American troops as individual replacements, whereas Pershing sought to field American units as an independent force. These units were assigned to the depleted French and British Empire commands on 28 March. A Supreme War Council of Allied forces was created at the Doullens Conference on 5 November 1917. General Foch was appointed as supreme commander of the allied forces. Haig, Petain, and Pershing retained tactical control of their respective armies; Foch assumed a coordinating rather than a directing role, and the British, French, and US commands operated largely independently.
Following Operation Michael, Germany launched Operation Georgette against the northern English Channel ports. The Allies halted the drive after limited territorial gains by Germany. The German Army to the south then conducted Operations Blücher and Yorck, pushing broadly towards Paris. Operation Marne was launched on 15 July, attempting to encircle Reims and beginning the Second Battle of the Marne. The resulting counterattack, starting the Hundred Days Offensive, marked the first successful Allied offensive of the war.
By 20 July, the Germans were back across the Marne at their starting lines, having achieved little. Following this last phase of the war in the West, the German Army never regained the initiative. German casualties between March and April 1918 were 270,000, including many highly trained storm troopers.
Meanwhile, Germany was falling apart at home. Anti-war marches became frequent and morale in the army fell. Industrial output was 53% of 1913 levels.