Why did Russia leave World War I after the Russian Revolution?

Russia’s withdrawal from World War I was driven by the internal collapse of the Russian military and the political objectives of the Bolsheviks following the Russian Revolution.12

By 1917, the Russian army was demoralized by years of poor leadership, inadequate supplies, and heavy losses. The March Revolution further eroded discipline, notably through the Petrograd Soviet’s "Order No. 1," which encouraged soldiers to form committees and challenge their officers.23

When Vladimir Lenin and the Bolsheviks seized power in the October Revolution, ending the war became a top priority. Lenin feared that if the war continued, soldiers would abandon the front to claim land, potentially toppling his new regime. He also hoped an armistice would trigger revolutionary unrest in the West.12

Despite harsh terms, Lenin insisted on signing the Treaty of Brest-Litovsk in March 1918 to secure peace with the Central Powers, which allowed the Bolsheviks to consolidate their power and survive internal political opposition.12