51 The End of World War I

American Entry into WWI

The American entry into World War I came in April 1917, after two and a half years of efforts by President Woodrow Wilson to keep the United States neutral.

Learning Objectives

Explain why the United States entered WWI

Key Takeaways

Key Points

  • After World War I began in 1914, the United States proclaimed a policy of strict neutrality, with President Wilson trying to broker peace.
  • American public opinion was strongly divided, with most Americans until early 1917 supporting the United States staying out of the war.
  • When the German U-boat U-20 sank the British liner Lusitania on May 7, 1915, with 128 U.S. citizens aboard, Wilson demanded an end to attacks on passenger ships as they were in violation of international law and of human rights; Germany complied.
  • Wilson came under pressure from war hawks led by former president Theodore Roosevelt, who denounced German acts as “piracy.” Public opinion, angry over the sinking of the Lusitania, began to sway in favor of entering the war.
  • In January 1917, Germany resumed unrestricted submarine warfare against their 19155 agreement with the U.S.
  • The German Foreign minister, Arthur Zimmermann, invited revolution-torn Mexico to join the war as Germany’s ally against the United States in the Zimmermann Telegram. This was intercepted by the British and given to the Americans, who saw it as a cause for war.
  • The United States declared war on the German Empire on April 6, 1917, and immediately began sending troops to France.

Key Terms

  • sinking of the Lusitania: On May 7, 1915, during the First World War, as Germany waged submarine warfare against the United Kingdom of Great Britain and Ireland, the Lusitania was identified and torpedoed by the German U-boat U-20 and sank in 18 minutes. The vessel went down 11 miles off the Old Head of Kinsale, Ireland, killing 1,198 and leaving 761 survivors. The sinking turned public opinion in many countries against Germany, contributed to the American entry into World War I, and became an iconic symbol in military recruiting campaigns.
  • Zimmermann Telegram: A secret diplomatic communication issued from the German Foreign Office in January 1917 that proposed a military alliance between Germany and Mexico in the event of the United States entering World War I against Germany. The proposal was intercepted and decoded by British intelligence. Revelation of the contents enraged American public opinion, especially after the German Foreign Secretary Arthur Zimmermann publicly admitted the telegram was genuine on March 3, and helped generate support for the United States declaration of war on Germany in April.
  • casus belli: A Latin expression meaning “an act or event that provokes or is used to justify war” (literally, “a case of war”). It involves direct offenses or threats against the nation declaring the war, whereas a casus foederis involves offenses or threats against its ally—usually one bound by a mutual defense pact. Either may be considered an act of war.

American Neutrality and the Lusitania

At the outbreak of World War I, the United States pursued a policy of non-intervention, avoiding conflict while trying to broker a peace. When the German U-boat U-20 sank the British liner RMS Lusitania on May 7, 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, and Wilson unsuccessfully tried to mediate a settlement. However, he also repeatedly warned that the United States would not tolerate unrestricted submarine warfare, which was in violation of international law. 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.”

American public opinion was divided, with most before early 1917 strongly of the opinion that the United States should stay out of the war. Opinion changed gradually, partly in response to German actions in Belgium and the sinking of the Lusitania, partly as German Americans lost influence, and partly in response to Wilson’s position that America had to play a role in making the world safe for democracy.

The general public showed little support for entering the war on the side of Germany. The great majority of German Americans and Scandinavian Americans, wanted the United States to remain neutral; however, at the outbreak of war, thousands of U.S. citizens tried to enlist in the German army. The Irish Catholic community, based in the large cities and often in control of the Democratic Party apparatus, was strongly hostile to helping Britain in any way, especially after the Easter uprising of 1916 in Ireland. Most Protestant church leaders in the United States, regardless of their theology, favored pacifistic solutions. Most of the leaders of the women’s movement, typified by Jane Addams, likewise sought brokerage of peace. The most prominent opponent of war was industrialist Henry Ford, who personally financed and led a peace ship to Europe to try to negotiate among the belligerents; no negotiations resulted.

The painting shows a large passenger ocean liner leaning to the side, on fire and smoking, with passengers aboard.
Sinking of the Lusitania: A 1915 painting of the sinking of the passenger ship Lusitania, an event which shifted American public opinion toward entering WWI and became a symbol for the fight against Germany.

The Zimmermann Telegram and Declaration 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 U.S. embassy in the UK. From there it made its way to President Wilson, who released it to the public. Americans considered the Zimmermann Telegram casus belli.

Popular sentiment in the United States at that time was anti-Mexican as well as anti-German, while in Mexico there was considerable anti-American sentiment. General John J. Pershing had long been chasing the revolutionary Pancho Villa and carried out several cross-border raids. News of the telegram further inflamed tensions between the United States and Mexico.

Wilson asked Congress for “a war to end all wars” that would “make the world safe for democracy” and eliminate militarism from the globe. He argued that the war was important and the U.S. thus must have a voice in the peace conference. After the sinking of seven U.S. merchant ships by submarines and the publication of the Zimmermann telegram, Wilson called for war on Germany, which the U.S. Congress declared on April 6, 1917.

The United States was never formally a member of the Allies but became a self-styled “Associated Power.” It initially had a small army, but after the passage of the Selective Service Act drafted 2.8 million men, and by summer 1918 was sending 10,000 fresh soldiers to France every day. In 1917, the U.S. Congress gave citizenship to Puerto Ricans drafted to participate in World War I as part of the Jones Act. If Germany believed it would be many more months before American soldiers would arrive and that their arrival could be stopped by U-boats, it had miscalculated.

The United States Navy sent a battleship group to Scapa Flow to join the British Grand Fleet, destroyers to Queenstown, Ireland, and submarines to help guard convoys. Several regiments of U.S. Marines were also dispatched to France. The British and French wanted American units to reinforce their troops already on the battle lines and not waste scarce shipping on supplies. General John J. Pershing, American Expeditionary Forces (AEF) commander, refused to break up American units to be used as filler material. 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 and earned 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 due to the large loss of life that resulted.

President Wilson before Congress, announcing the break in official relations with the German Empire on February 3, 1917.
America Enters WWI: President Wilson before Congress, announcing the break in official relations with the German Empire on February 3, 1917. Two months later, the U.S. declared war on Germany.

The Treaty of Brest-Litovsk

The Russian government collapsed in March 1917. The subsequent October Revolution followed by a further military defeat brought the Russians to terms with the Central Powers via the Treaty of Brest-Litovsk, which granted the Germans a significant victory and resulted in Russia exiting the war and breaking ties with the Allied Powers.

Learning Objectives

State the consequences of the Treaty of Brest-Litovsk

Key Takeaways

Key Points

  • In March 1917, demonstrations in Russia culminated in the abdication of Tsar Nicholas II and the appointment of a weak provisional government that shared power with the Petrograd Soviet socialists.
  • This arrangement led to confusion and chaos both at the front and at home, with the Russian army becoming 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 October Revolution, which put the Bolsheviks into power, 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 Ukraine unopposed, the new government acceded to the Treaty of Brest-Litovsk on March 3, 1918.
  • The treaty ceded vast territories, including Finland, the Baltic provinces, parts of Poland, and Ukraine, to the Central Powers.
  • The treaty was effectively terminated in November 1918 when Germany surrendered to the Allies.

Key Terms

  • Russian Civil War: A multi-party war in the former Russian Empire immediately after the Russian Revolutions of 1917, as many factions vied to determine Russia’s political future. The two largest combatant groups were the Red Army, fighting for the Bolshevik form of socialism, and the loosely allied forces known as the White Army, which included diverse interests favoring monarchism, capitalism, and alternative forms of socialism, each with democratic and antidemocratic variants. In addition, rival militant socialists and non-ideological Green armies fought against both the Bolsheviks and the Whites. The Red Army defeated the White Armed Forces of South Russia in Ukraine and the army led by Admiral Aleksandr Kolchak in Siberia in 1919. The remains of the White forces commanded by Pyotr Nikolayevich Wrangel were beaten in Crimea and evacuated in late 1920. Lesser battles continued on the periphery for two more years, and minor skirmishes with the remnants of the White forces in the Far East continued well into 1923.
  • October Revolution: A seizure of state power instrumental in the larger Russian Revolution of 1917. It took place with an armed insurrection in Petrograd on October 25, 1917, and followed and capitalized on the February Revolution of the same year, which overthrew the Tsarist autocracy and resulted in a provisional government. During this time, urban workers began to organize into councils (Russian: soviet) wherein revolutionaries criticized the provisional government and its actions. This uprising overthrew the provisional government and gave the power to the local soviets.
  • Eastern Front of World War I: A theater of operations that encompassed at its greatest extent the entire frontier between the Russian Empire and Romania on one side and the Austro-Hungarian Empire, Bulgaria, the Ottoman Empire, and the German Empire on the other. It stretched from the Baltic Sea in the north to the Black Sea in the south, included most of Eastern Europe, and stretched deep into Central Europe as well. The term contrasts with “Western Front,” which was fought in Belgium and France.
  • Treaty of Brest-Litovsk: A peace treaty signed on March 3, 1918, between the new Bolshevik government of Soviet Russia and the Central Powers (Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire), that ended Russia’s participation in World War I.

The Treaty of Brest-Litovsk was a peace treaty signed on March 3, 1918, between the new Bolshevik government of Soviet Russia and the Central Powers (Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire ), that ended Russia’s participation in World War I. The treaty was signed at Brest-Litovsk after two months of negotiations and was forced on the Bolshevik government by the threat of further advances by German and Austrian forces. According to the treaty, Soviet Russia defaulted on all of Imperial Russia’s commitments to the Triple Entente alliance.

The treaty was effectively terminated in November 1918 when Germany surrendered to the Allies. However, in the meantime it provided some relief to the Bolsheviks, already fighting the Russian Civil War, by the renouncement of Russia’s claims on Poland, Finland, Estonia, Latvia, Belarus, Ukraine, and Lithuania.


By 1917, Germany and Imperial Russia were in a stalemate on the Eastern Front of World War I. At the time, the Russian economy nearly collapsed under the strain of the war effort. The large numbers of war casualties and persistent food shortages in the major urban centers brought about civil unrest, known as the February Revolution, that forced Tsar Nicholas II to abdicate. The Russian provisional government that replaced the Tsar (initially presided by prince Georgy Lvov, later by Alexander Kerensky), decided to continue the war on the Entente side. Foreign Minister Pavel Milyukov sent the Entente Powers a telegram, known as the Milyukov note, affirming that the provisional government would continue the war with the same aims as Imperial Russia.

The pro-war provisional government was opposed by the self-proclaimed Petrograd Soviet of Workers’ and Soldiers’ Deputies, dominated by leftist parties. Its Order No. 1 called for an overriding mandate to soldier committees rather than army officers. The Soviet started to form its own paramilitary power, the Red Guards, in March 1917.

The position of the provisional government led the Germans to offer support to the Russian opposition, the Communist Party (Bolsheviks) in particular, who were proponents of Russia’s withdrawal from the war. In April 1917, Germany allowed Bolshevik leader Vladimir Lenin to return to Russia from his exile in Switzerland and offered him financial help. Upon his arrival in Petrograd, Lenin proclaimed his April Theses, which included a call to turn all political power over to workers’ and soldiers’ soviets (councils) and an immediate withdrawal of Russia from the war. Throughout 1917, Bolsheviks spread defeatist and revolutionary propaganda calling for the overthrow of the provisional government and an end to the war. Following the disastrous failure of the Kerensky Offensive, discipline in the Russian army deteriorated completely. Soldiers would disobey orders, often under the influence of Bolshevik agitation, and allowed soldiers’ committees to take control of their units after deposing the officers. Russian and German soldiers occasionally left their positions and fraternized.

The defeat and ongoing hardships of war led to anti-government riots in Petrograd headed by the Bolsheviks, the “July Days” of 1917. Several months later on November 7, Red Guards seized the Winter Palace and arrested the provisional government in what is known as the October Revolution.

The newly established Soviet government decided to end Russia’s participation in the war with Germany and its allies. On October 26, 1917, Vladimir Lenin signed the Decree on Peace, which was approved by the Second Congress of the Soviet of Workers’, Soldiers’, and Peasants ‘ Deputies. The Decree called “upon all the belligerent nations and their governments to start immediate negotiations for peace” and proposed an immediate withdrawal of Russia from World War I. Leon Trotsky was appointed Commissar of Foreign Affairs in the new Bolshevik government. In preparation for peace talks with the representatives of the German government and other Central Powers, Leon Trotsky appointed his good friend Adolph Joffe to represent the Bolsheviks at the peace conference.

Terms of the Treaty and its Effects

On December 15, 1917, an armistice between Soviet Russia and the Central Powers was concluded and fighting stopped. On December 22, peace negotiations began at Brest-Litovsk. The Treaty of Brest-Litovsk was signed on March 3, 1918. The signatories were Bolshevik Russia signed by Grigori Yakovlovich Sokolnikov on the one side and the German Empire, Austria-Hungary, Bulgaria, and Ottoman Empire on the other. The treaty marked Russia’s final withdrawal from World War I as an enemy of her co-signatories, on unexpectedly humiliating terms.

Signing of armistice between Russia and Germany, shows German delegates (on the left) and Soviet delegates (on the right) sitting and standing along a long table, signing the Treaty.
Treaty of Brest-Litovsk: A photo of the signing of armistice between Russia and Germany on March 3, 1918. The treaty marked Russia’s final withdrawal from World War I and resulted in Russia losing major territorial holdings.

In the treaty, Bolshevik Russia ceded the Baltic States to Germany; they were meant to become German vassal states under German princelings. Russia ceded its province of Kars Oblast in the South Caucasus to the Ottoman Empire and recognized the independence of Ukraine. Further, Russia agreed to pay six billion German gold marks in reparations. Historian Spencer Tucker says, “The German General Staff had formulated extraordinarily harsh terms that shocked even the German negotiator.” Congress Poland was not mentioned in the treaty, as Germans refused to recognize the existence of any Polish representatives, which in turn led to Polish protests. When Germans later complained that the Treaty of Versailles of 1919 was too harsh, the Allies (and historians favorable to the Allies) responded that it was more benign than Brest-Litovsk.

With the adoption of the Treaty of Brest-Litovsk, the Entente no longer existed. 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 material for the Central Powers war effort. 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 Treaty of Brest-Litovsk lasted just over eight months. Germany renounced the treaty and broke diplomatic relations with Soviet Russia on November 5. The Ottoman Empire broke the treaty after just two months by invading the newly created First Republic of Armenia in May 1918. In the Armistice of November 11, 1918, that ended World War I, one of the first conditions was the complete abrogation of the Brest-Litovsk treaty. Following the German capitulation, the Bolshevik legislature annulled the treaty on November 13, 1918. In the year after the armistice, the German Army withdrew its occupying forces from the lands gained in Brest-Litovsk, leaving behind a power vacuum that various forces subsequently attempted to fill. In the Treaty of Rapallo, concluded in April 1922, Germany accepted the Treaty’s nullification, and the two powers agreed to abandon all war-related territorial and financial claims against each other.

The Treaty of Brest-Litovsk marked a significant contraction of the territory controlled by the Bolsheviks or that they could lay claim to as effective successors of the Russian Empire. While the independence of Finland and Poland was already accepted in principle, the loss of Ukraine and the Baltics created, from the Bolshevik perspective, dangerous bases of anti-Bolshevik military activity in the subsequent Russian Civil War (1918–1922). Indeed, many Russian nationalists and some revolutionaries were furious at the Bolsheviks’ acceptance of the treaty and joined forces to fight them. Non-Russians who inhabited the lands lost by Bolshevik Russia in the treaty saw the changes as an opportunity to set up independent states not under Bolshevik rule. Immediately after the signing of the treaty, Lenin moved the Soviet Russian government from Petrograd to Moscow.

The fate of the region and the location of the eventual western border of the Soviet Union was settled in violent and chaotic struggles over the course of the next three-and-a-half years.

The British Naval Blockade

Soon after the outbreak of hostilities, Britain began a naval blockade of Germany. This strategy proved effective, cutting off vital military and civilian supplies and helping the Allies to eventually win the war.

Learning Objectives

Evaluate the effectiveness of the British Naval Blockade

Key Takeaways

Key Points

  • Naval warfare in World War I was mainly characterized by the efforts of the Allied Powers, with their larger fleets and surrounding position, to blockade the Central Powers by sea. The Central Powers used submarines and radars to try t  break that blockade or establish their own blockade of the United Kingdom and France.
  • Shortly after the outbreak of the war, the British navy, the largest and most powerful in the world at that time, began a naval blockade of Germany, cutting off vital military and civilian supplies.
  • Britain mined international waters to prevent any ships from entering entire sections of ocean, causing danger to even neutral ships.
  • The German Board of Public Health in December 1918 claimed that 763,000 German civilians died from starvation and disease caused by the blockade through December 1918.
  • The blockade also had a detrimental effect on the U.S. economy and the U.S. government protested the blockade vigorously.
  • It is considered one of the key elements in the eventual Allied victory in the war, although historians have argued about its importance.

Key Terms

  • German Revolution of 1918–19: Civil conflict in the German Empire at the end of the First World War resulted in the replacement of Germany’s Imperial government with a republic. The revolutionary period lasted from November 1918 until the establishment in August 1919 of a republic that later became known as the Weimar Republic.
  • Blockade of Germany: A prolonged naval operation conducted by the Allied Powers, especially Great Britain, during and after World War I to restrict the maritime supply of goods to the Central Powers, which included Germany, Austria-Hungary, and Turkey.

The Blockade of Germany, or the Blockade of Europe, occurred from 1914 to 1919. It was a prolonged naval operation conducted by the Allied Powers, especially Great Britain, during and after World War I to restrict the maritime supply of goods to the Central Powers, which included Germany, Austria-Hungary, and Turkey. It is considered one of the key elements in the eventual Allied victory in the war. The German Board of Public Health claimed that 763,000 German civilians died from starvation and disease caused by the blockade through December 1918. An academic study done in 1928 put the death toll at 424,000.

Both the German Empire and the United Kingdom relied heavily on imports to feed their population and supply their war industry. Imports of foodstuffs and war material of all European belligerents came primarily from the Americas and had to be shipped across the Atlantic Ocean, so Britain and Germany both aimed to blockade each other. The British had the Royal Navy, which was superior in numbers and could operate throughout the British Empire, while the German Kaiserliche Marine surface fleet was mainly restricted to the German Bight and used commerce raiders and unrestricted submarine warfare to operate elsewhere.

The British—with their overwhelming sea power—established a naval blockade of Germany immediately on the outbreak of war in August 1914, issuing a comprehensive list of contraband that all but prohibited American trade with the Central powers. In early November 1914 they declared the North Sea a war zone, with any ships entering at their own risk. The blockade was unusually restrictive in that even foodstuffs were considered “contraband of war.” There were complaints about breaches of international law; however, most neutral merchant vessels agreed to dock at British ports to be inspected and then escorted—less any “illegal” cargo destined for Germany—through the British minefields to their destinations.

Did the Blockade Win the War?

The first official accounts of the blockade, written by Professor A. C. Bell and Brigadier-General Sir James E. Edmonds, differed in their accounts of its effects upon German food supplies. Bell—who employed German data—argued that the blockade led to revolutionary uprisings in Germany and caused the collapse of the Kaiser′s administration. Edmonds, supported by Colonel Irwin L. Hunt (who was in charge of civil affairs in the American occupied zone of the Rhineland), held that food shortages were a post-armistice phenomenon caused solely by the disruptions of the German Revolution of 1918–19.

More recent studies also disagree on the severity of the blockade′s impact on the affected populations at the time of the revolution and the armistice. Some hold that the blockade starved Germany and the Central Powers into defeat in 1918, but others maintain that while the German population did indeed go hungry as a result of the blockade, Germany′s rationing system kept all but a few from actually starving to death. German success against the Russians on the Eastern Front culminating in the Treaty of Brest-Litovsk gave Germany access to the resources of Poland and other eastern territories, which did much to counter the effects of the blockade. The armistice on November 11 was forced by events on the Western Front rather than any actions of the civilian population. Germany’s largest ally, Austria-Hungary, had already signed an armistice on November 3, exposing Germany to an invasion from the south.

Nevertheless, it is accepted that the blockade made a large contribution to the outcome of the war; by 1915, Germany′s imports had already fallen by 55% from their prewar levels and the exports were 53% of what they were in 1914. Apart from leading to shortages in vital raw materials such as coal and metals, the blockade also deprived Germany of supplies of fertilizer that were vital to agriculture. This latter led to staples such as grain, potatoes, meat, and dairy products becoming so scarce by the end of 1916 that many people were obliged to instead consume ersatz products including Kriegsbrot (“war bread”) and powdered milk. The food shortages caused looting and riots not only in Germany, but also in Vienna and Budapest. Austria-Hungary even hijacked ships on the Danube that were meant to deliver food to Germany.

The German government made strong attempts to counter the effects of the blockade; the Hindenburg Programme of German economic mobilization launched in August 1916 was designed to raise productivity by the compulsory employment of all men between the ages of 17 and 60. A complicated rationing system introduced in January 1915 aimed to ensure that a minimum nutritional need was met, with “war kitchens” providing cheap mass meals to impoverished civilians in larger cities. All these schemes enjoyed only limited success, and the average daily diet of 1,000 calories was insufficient to maintain a good standard of health, resulting by 1917 in widespread disorders caused by malnutrition such as scurvy, tuberculosis, and dysentery.

The blockade also had a detrimental effect on the U.S. economy. Under pressure especially from commercial interests wishing to profit from wartime trade with both sides, the U.S. government protested vigorously. Britain did not wish to antagonize the U.S., but cutting off trade to the enemy seemed a more pressing goal. Eventually, Germany′s submarine campaign and the subsequent sinking of the RMS Lusitania and other civilian vessels with Americans on board did far more to antagonize U.S. opinion than the blockade had.

The Grand Fleet sailing in parallel columns during the First World War
British Grand Fleet: The Grand Fleet sailing in parallel columns during the First World War. The British Navy was responsible for the successful Blockade of Germany, which cut off vital supplies from Germany and contributed to the defeat of the Central Powers.

The Hundred Days Offensive

The Hundred Days Offensive was the final period of World War I, during which the Allies launched a series of offensive attacks against the Central Powers that pushed the Germans out of France and led to their defeat.

Learning Objectives

Describe the events of the Hundred Days Offensive and how they led to the end of the war

Key Takeaways

Key Points

  • After a stunning German offensive along the Western Front in the spring of 1918, the Allies rallied and drove back the Germans in a series of successful offensives, known collectively as the Hundred Days Offensives.
  • The Hundred Days Offensives began with the Battle of Amiens in August 1918, with an attack by more than 10 Allied divisions—Australian, Canadian, British and French forces—with more than 500 tanks.
  • Total German losses were estimated at 30,000 men, while the Allies suffered about 6,500 killed, wounded and missing; the resulting collapse in German morale led German General Erich Ludendorff to dub it “the Black Day of the German Army.”
  • The allies continued offensives on several points on the Western Front, eventually forcing the Germans behind the Hindenburg Line, which had been a stable defensive line for the Germans.
  • With the military faltering and widespread loss of confidence in the Kaiser, Germany moved towards surrender.
  • On November 4, 1918, the Austro-Hungarian empire agreed to an armistice, and Germany, which had its own trouble with revolutionaries, agreed to an armistice on November 11, 1918, ending the war in victory for the Allies.

Key Terms

  • Weimar Republic: An unofficial historical designation for the German state between 1919 and 1933. The name derives from the city of Weimar, where its constitutional assembly first took place. In its 14 years, it faced numerous problems, including hyperinflation, political extremism (with paramilitaries – both left- and right-wing); and contentious relationships with the victors of the First World War. Hitler’s seizure of power brought the republic to an end; as democracy collapsed, a single-party state founded the Nazi era.
  • Spring Offensive: A series of German attacks along the Western Front during the First World War, beginning on March 21, 1918, that marked the deepest advances by either side since 1914. The Germans realized that their only remaining chance of victory was to defeat the Allies before the overwhelming human and matériel resources of the United States could be fully deployed. They also had the temporary advantage in numbers afforded by the nearly 50 divisions freed by the Russian surrender.
  • Hindenburg Line: A German defensive position of World War I, built during the winter of 1916-1917 on the Western Front from Arras to Laffaux, near Soissons on the Aisne. Construction of this position in France was begun by the Germans in September 1916, to make retirement from the Somme front possible and counter an anticipated increase in the power of Anglo-French attacks in 1917.
  • Hundred Days Offensive: The final period of the First World War, during which the Allies launched a series of offensives against the Central Powers on the Western Front from August 8 to November 11, 1918, beginning with the Battle of Amiens.

The Hundred Days Offensive was the final period of the First World War, during which the Allies launched a series of offensives against the Central Powers on the Western Front from August 8 to November 11, 1918, beginning with the Battle of Amiens. The offensive essentially pushed the Germans out of France, forcing them to retreat beyond the Hindenburg Line, and was followed by an armistice. The term “Hundred Days Offensive” does not refer to a specific battle or unified strategy, but rather the rapid series of Allied victories starting with the Battle of Amiens.


The Spring Offensive of the German Army on the Western Front began in March 1918 with Operation Michael and had petered out by July. The Germans advanced to the river Marne but failed to achieve a decisive breakthrough. When Operation Marne-Rheims ended in July, the Allied supreme commander Ferdinand Foch, ordered a counter-offensive which became known as the Second Battle of the Marne. The Germans, recognizing their untenable position, withdrew from the Marne towards the north. For this victory, Foch was granted the title Marshal of France.

Foch thought the time had arrived for the Allies to return to the offensive. The American Expeditionary Force (AEF, General John J. Pershing), was present in France in large numbers and invigorated the Allied armies. Pershing was keen to use his army in an independent role. The British Expeditionary Force (BEF) had also been reinforced by large numbers of troops returned from the Sinai and Palestine Campaign and the Italian Front, as well as replacements held back in Britain by the Prime Minister, David Lloyd George.

A number of proposals were considered and finally, Foch agreed on a proposal by Field Marshal Sir Douglas Haig, Commander-in-Chief (C-in-C) of the BEF, to strike on the River Somme, east of Amiens and south-west of the site of the 1916 Battle of the Somme, with the intention of forcing the Germans away from the vital Amiens-Paris railway. The Somme was chosen as a suitable site for several reasons. As in 1916, it marked the boundary between the BEF and the French armies, in this case defined by the Amiens-Roye road, allowing the two armies to cooperate. Also, the Picardy countryside provided a good surface for tanks, which was not the case in Flanders. Finally, the German defenses, manned by the German 2nd Army (General Georg von der Marwitz), were relatively weak, having been subjected to continual raiding by the Australians in a process termed peaceful penetration.

Final Battles of WWI

The Hundred Days Offensive began on August 8, 1918, with the Battle of Amiens. The battle involved over 400 tanks and 120,000 British, Dominion, and French troops, and by the end of its first day a gap 15 miles long had been created in the German lines. The defenders displayed a marked collapse in morale, causing German General Erich Ludendorff to refer to this day as the “Black Day of the German army.” After an advance as far as 14 miles, German resistance stiffened, and the battle was concluded on August 12.

Rather than continuing the Amiens battle past the point of initial success, as had been done so many times in the past, the Allies shifted their attention elsewhere. Allied leaders had now realized that to continue an attack after resistance had hardened was a waste of lives, and it was better to turn a line than to try to roll over it. They began to undertake attacks in quick order to take advantage of successful advances on the flanks, then broke them off when the initial impetus was lost.

British and Dominion forces launched the next phase of the campaign with the Battle of Albert on August 21. The assault was widened by French and further British forces in the following days. During the last week of August, the Allied pressure along a 68-mile front against the enemy was heavy and unrelenting. From German accounts, “Each day was spent in bloody fighting against an ever and again on-storming enemy, and nights passed without sleep in retirements to new lines.”

Faced with these advances, on September 2 the German Supreme Army Command issued orders to withdraw to the Hindenburg Line in the south.

September saw the Allies advance to the Hindenburg Line in the north and center. The Germans continued to fight strong rear-guard actions and launched numerous counterattacks on lost positions, but only a few succeeded, and those only temporarily. Contested towns, villages, heights, and trenches in the screening positions and outposts of the Hindenburg Line continued to fall to the Allies, with the BEF alone taking 30,441 prisoners in the last week of September. The Germans retreated to positions along or behind the Hindenburg Line.

In nearly four weeks of fighting beginning August 8, over 100,000 German prisoners were taken. The German High Command realized that the war was lost and made attempts to reach a satisfactory end. The day after that battle, Ludendorff said: “We cannot win the war any more, but we must not lose it either.”

The street is bordered by houses in ruin.
The Hundred Days Offensive: September 1, 1918, Péronne (Somme). A machine gun position established by the Australian 54th Battalion during its attack on German forces in the town.

The final assault on the Hindenburg Line began with the Meuse-Argonne Offensive, launched by French and American troops on September 27. The following week, cooperating French and American units broke through in Champagne at the Battle of Blanc Mont Ridge, forcing the Germans off the commanding heights and closing toward the Belgian frontier. On October 8, the line was pierced again by British and Dominion troops at the Battle of Cambrai.

With the military faltering and widespread loss of confidence in the Kaiser, Germany moved towards surrender. Prince Maximilian of Baden took charge of a new government as Chancellor of Germany to negotiate with the Allies. Negotiations with President Wilson began immediately in the hope that he would offer better terms than the British and French. Wilson demanded a constitutional monarchy and parliamentary control over the German military. There was no resistance when the Social Democrat Philipp Scheidemann declared Germany a republic on November 9. The Kaiser, kings, and other hereditary rulers were removed from power and Wilhelm fled to exile in the Netherlands. Imperial Germany was dead; a new Germany had been born as the Weimar Republic.

Soon after, the Germans signed the Armistice of Compiègne, which ended the fighting on the Western Front. It went into effect at 11 a.m. Paris time on November 11, 1918 (“the eleventh hour of the eleventh day of the eleventh month”), and marked a victory for the Allies and a complete defeat for Germany, although not formally a surrender. Although the armistice ended the actual fighting, it took six months of negotiations at the Paris Peace Conference to conclude the peace treaty, the Treaty of Versailles.

A large group of men in military outfits are smiling and raising up their helmets.
Armistice of Compiègne: Men of US 64th Regiment, 7th Infantry Division, celebrate the news of the Armistice, 11 November 1918, which ended the hostilities of WWI.


Icon for the Creative Commons Attribution 4.0 International License

The End of World War I by Boundless.com is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

Share This Book