What did Lenin want from World War I?

Answer 1

Lenin promised the Russians that if he were to gain power, he would immediately pull Russia out of WW I, which in fact he did. It was sort of like a campaign promise, except that Lenin was not conducting a campaign for election, he was conducting a revolution. But revolutions depend upon popular support as much as elections do. WW I was extremely unpopular in Russia, so this proved to be a very attractive promise.

Answer 2

Lenin wanted World War 1 to be a catalyst for a revolution to overthrow first the Tsarist regime and then the Provisional Government. Lenin hoped that the heavy losses Russia was taking in the war would lead to more and more dissatisfaction with the ruling class to a point where the country would rise in revolt to end it.

Lenin advocated a concept called "revolutionary defeatism." This meant that soldiers and workers in the war effort were simply fighting for the interests of the bourgeoisie rather than for their own. Thus, a defeat in the war could become a victory for a revolution because the interests of the bourgeoisie would have been defeated. Not everyone agreed with him.

Lenin's slogan for this idea was "Turn imperialistic war into civil war."