Final answer:
Russia withdrew from WWI due to severe military shortages, low morale, internal dissent, and the eventual overthrow of the Tsarist government, culminating in a peace treaty after the Bolshevik rise to power.
Step-by-step explanation:
The reasons for Russia's withdrawal from World War I are multifaceted, involving military, social, and political factors. The Russian Army faced crippling supply shortages, sustaining massive casualties without adequate munitions, particularly in artillery. Morale was exceedingly low, not only among the soldiers but also on the home front where people suffered from food shortages and widespread discontent with the Tsarist government. These dire circumstances, accompanied by a staggering number of desertions, set the stage for the revolutionary movements that eventually led to the overthrow of Tsar Nicholas II and the establishment of a provisional government. This provisional government continued the war effort briefly, but internal strife and lack of support led to its replacement by the Bolsheviks, who subsequently negotiated Russia's exit from the war with the Treaty of Brest-Litovsk in 1918.