Imperialist war is the eve of socialist revolution. And this not only because the horrors of the war give rise to proletarian revolt—no revolt can bring about socialism unless the economic conditions for socialism are ripe—but because state-monopoly capitalism is a complete material preparation for socialism, the threshold of socialism, a rung on the ladder of history between which and the rung called socialism there are no intermediate rungs.
- Impending Catastrophe and How to Combat it by Lenin