What event led to Russia's withdrawal from World War I?

The Bolshevik Revolution was a critical event that led to Russia's withdrawal from World War I. In 1917, the Bolsheviks, a radical socialist faction led by Vladimir Lenin, overthrew the Russian Provisional Government, which had replaced the Tsar after the February Revolution. The new Bolshevik government was strongly opposed to the war, viewing it as an imperialistic conflict that was not in the interests of the working class.

Once in power, the Bolsheviks sought to end Russia's involvement in the war. They initiated peace talks with Germany, resulting in the Treaty of Brest-Litovsk in March 1918, which officially marked Russia's exit from the conflict. This treaty had significant implications for the war and reshaped the geopolitical landscape, as Russia ceded substantial territories to Germany.

Other options presented do not directly relate to the cause of Russia's withdrawal. The death of Lenin occurred after the revolution and was not a factor in the decision to leave the war. Similarly, the German occupation of Moscow did not happen; instead, the internal upheaval within Russia led to its exit. The German-Japanese alliance is not relevant to Russia's withdrawal as Japan was not a primary player against Russia during World War I