Changes in the Allied Forces

The order matters: the USA declared war in April 1917, before the Bolsheviks took power in Russia in November. American entry was not a response to the later Bolshevik withdrawal.

Why the Bolsheviks took Russia out of the war

By 1917, military defeats, heavy casualties and shortages of food and fuel had undermined support for Russia’s government. Tsar Nicholas II abdicated in March 1917, but the Provisional Government which replaced him continued fighting. Its failed summer offensive further weakened confidence in the government and contributed to desertion and unrest.

Vladimir Lenin’s Bolsheviks offered a different policy. Their slogan, ‘Land, Peace and Bread’, appealed to people exhausted by war and hardship. Germany helped Lenin return to Russia in April 1917 because it hoped he would destabilise its enemy. When the Bolsheviks overthrew the Provisional Government in November, Lenin sought peace with Germany rather than continuing the Allied war effort.

A ceasefire followed in December 1917. In March 1918, Russia signed the Treaty of Brest-Litovsk with Germany and its allies. Russia accepted extensive territorial losses in exchange for leaving the war. The revolution therefore changed more than Russia’s government: it removed a major participant from the conflict.

What Russia’s withdrawal meant for Germany

Russia had forced Germany to divide its army between east and west. Its withdrawal removed this major eastern opponent, allowing Germany to transfer troops to the Western Front. Britain and France now faced the danger of a more concentrated German attack without Russia putting pressure on Germany from the east.

Germany also gained access to farmland and resources through the settlement. These gains offered some relief from the shortages caused by the British naval blockade. However, they should not be confused with a complete solution to Germany’s wartime difficulties.

German leaders saw withdrawal as an opportunity for a decisive offensive against Britain and France. Yet the opportunity was temporary: the USA had already entered the war, and American military strength would grow as troops arrived in Europe. This combination helped shape Germany’s decision to launch the Spring Offensive in 1918—attack while additional troops from the east were available, but before the Americans could deploy their full strength.

Why the USA initially remained neutral

When war began in 1914, many Americans wanted to avoid involvement in a distant European conflict. This reflected isolationism: a preference for staying out of European wars. President Woodrow Wilson initially maintained neutrality.

Neutrality did not mean the USA was economically disconnected from the war. American businesses supplied the Allies with food, raw materials, weapons and machinery, while American loans helped finance their war effort. These connections supported Britain and France even before the USA became a military participant.

How submarine warfare brought the USA closer to war

Germany used U-boats to attack shipping supplying Britain. Unrestricted submarine warfare meant attacking ships within declared war zones without warning, including neutral vessels. This threatened American trade and American lives.

In May 1915, a German submarine sank the British passenger liner Lusitania, killing 128 Americans. The sinking caused outrage and increased hostility towards Germany, but Wilson did not declare war. Germany subsequently restricted its submarine attacks, and in 1916 made the Sussex pledge to limit attacks on passenger and merchant shipping.

Germany resumed unrestricted submarine warfare on 1 February 1917. Its leaders hoped to cut Britain’s supplies and force it out of the war before the USA could make a significant military contribution. They knowingly risked American entry. Attacks on American ships during February and March demonstrated that American citizens and commerce remained in danger. This renewed campaign was the main immediate reason for Wilson’s move towards war.

Why the Zimmermann Telegram mattered

British intelligence intercepted the Zimmermann Telegram in January 1917. Germany proposed an alliance with Mexico against the USA, offering support for recovering Texas, Arizona and New Mexico. Britain passed the message to Wilson in February, and it became public in early March.

The proposal made Germany appear to threaten American security directly, not simply American shipping overseas. Together with continued submarine attacks, it helped turn public and political opinion towards war. It was a proposed alliance, not an actual Mexican attack.

Wilson asked Congress for a declaration of war on 2 April. The USA formally declared war on Germany on 6 April 1917.

American entry: immediate support, delayed military strength

American entry strengthened Allied confidence and brought the USA’s economic resources firmly behind the war effort. Its finance and supplies—including food, oil, coal, weapons and machinery—helped sustain Britain and France. This became especially important as Russia’s future in the war grew uncertain and it eventually withdrew.

The military impact was not immediate. It took months for American soldiers to reach the front lines, so a declaration of war did not instantly replace the pressure Russia had exerted on the Eastern Front. Nevertheless, the prospect of fresh American troops gave the Allies hope and created a serious long-term threat to Germany.

The two changes therefore worked together to create a strategic deadline for Germany. Russia’s departure increased the forces Germany could use in the west; American entry meant that waiting would allow its opponents to become stronger. Germany’s decision to seek a rapid victory in 1918 grew out of both developments, not either one alone.