Massive military defeat in WWI which destabilized Russia. If the Whites were better organized, the result could easily have been a very bigoted nationalist dictatorship instead.

If Kerensky had been successful maybe Russia would have ended up with a Nordic democratic socialism model. Not that he had the wherewithal to be successful ( Ordered an ill-fated military offensive against Austro-Hungarian forces in June/July 1917 that resulted in heavy losses damaged him politically), but there was a brief shining moment prior to the Germans injecting Lenin back into Russia. The German gambit that sending Lenin into Russia would take Russia out of the war paid off much more handsomely than they could've imagined.

It was still a very bigoted nationalist dictatorship. People were sent to the gulag or killed otherwise, for instance through man made famine. Both minorities and so called enemies of the state. The most violent won. That's how one gets leaders like Stalin.

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