Snyder notes similarities between the two totalitarian regimes and also the enabling interactions that reinforced the destruction and the suffering that were brought to bear on noncombatants. Making use of many new primary and secondary sources from Central and Eastern Europe, Snyder brings scholarship to many forgotten, misunderstood, or incorrectly-remembered parts of the history, and he particularly notes that most of the victims were killed outside the concentration camps of the respective regimes.[1]Snyder in 2011 estimated that Hitler killed more than Stalin.[2]