The primary reason Russia exited World War I was the successful takeover of the Russian government in 1917 by the Bolsheviks in the Russian Revolution, which is also known as the October Revolution. The Bolsheviks did not support the war effort against Germany and its allies and like most of the population wanted an end to the rising death toll, economic deprivation and food shortages that the war had brought upon the country. Vladimir Lenin, the Bolshevik leader who took control of the new government after the revolution, viewed the war as a power struggle between imperialist nations and sought to divert Russia's efforts and resources towards building the new socialist state he had just helped to create.
Prior to the October Revolution, Russia had already suffered war casualties that reached almost 5,000,000 dead, missing or taken prisoner. The military defeats were increasing, morale was low and soldiers began to mutiny. By the end of the second year of the conflict, the Russian economy was approaching collapse as a result of the increasing demands of the war. The food shortages, coupled with an alarming rate of inflation, gave rise to strikes, mass protests and riots in the months leading to the Bolsheviks' seizure of power. In March of 1918, the year following the October Revolution, the new Bolshevik government and Germany signed the Treaty of Brest-Litovsk, which officially ended Russia's participation in World War I.