The Gulag Archipelago [Volume 1]: An Experiment in Literary Investigation ― The Classic Soviet History Memoir about the Bureaucracy of Terror (Gulag Archipelago, 1918-1956)

If you think the we were worse than the Soviets, you are either ignorant, or simply don't care. Mass murders on an industrial scale, planned starvation that killed millions, hundreds of thousands disappeared to the Gulag, mass forced resettlement of populations, and the terrorizing of millions to maintain control for decades. And that's just a few of the things done within their own boarders. I would suggest a few sources for further reading: Bloodlands: Europe Between Hitler and Stalin The Gulag Archipelago One Day in the Life of Ivan Denisovich