In power, socialism swelled the state and destroyed not just the “bourgeoisie” but the small-business owner, the family farmer, the artisan. All of this shocked non-Leninist socialists who hoped to end exploitation and alienation and break through to social democracy while still insisting on their class approach. These Marxists repudiated the Soviet Union as not socialism but a deformation, because of Russia, or Lenin, or Stalin.

After all, Marx had never advocated mass murder, but freedom. Nowhere did he say there should be collective farms formed by secret police coercion, mass deportations to frozen wastes, terrible famine. Of course, Marx had insisted that wage labor was “wage slavery,” private capital “exploitation” and “alienation,” the market “chaos,” and therefore that, to achieve lasting abundance and freedom, capitalism had to be “transcended.” The tragedy began unfolding with the very invention of “capitalism.”

Self-styled socialists in the nineteenth century, initially, had employed other terms – “the anti-social system,” “the system of bourgeois property” – but then hit upon this single all-encompassing notion whose essence (property relations, a mode of production), if replaced, would supposedly alter not merely the economy but the entire world, delivering abundance, social justice, and peace. The invention of “capitalism” was a stunning achievement for the socialists, in a way, but a tragedy for humanity, and ultimately, for the entire left, too.

Unlike Leninists, Social Democrats were never sure whether this “capitalism” would implode on its own, could be peacefully overcome inside parliaments by large worker-majority parties, or in the end required revolutionary intervention, but it had to go. Those Social Democrats who came to believe that “capitalism” was amenable to becoming more humane – capitalism with a human face – opened themselves up to accusations of being accomplices to exploitation and imperialism.

Once markets and private property were named and blamed as the source of evil, statization would be the consequence. A few socialists began, painfully, to recognize that there could be no freedom without markets and private property, but they were denounced as apostates. Compounding the tragedy of the left, traditional conservatives committed the gross error of inviting the fascists and Nazis to power in no small part because of the leftist threat and the hard-nosed view that differences between anticapitalist democratic socialists and Leninists were delusion. To top it all off, Social Democrats and Communists fought a bitter civil war over workers' allegiance.

Without Stalin there would have been no socialism, and without socialism, no Stalin.

— Stephen Kotkin, Stalin – Vol. II: Waiting for Hitler, 1929 – 1941