High Quality Content by WIKIPEDIA articles! A number of authors have carried out comparisons of Nazism and Stalinism, in which they have considered the issues of whether the two ideologies were similar or different, how these conclusions affect understanding of 20th century history, what relationship existed between the two regimes, and why both of them came to prominence at the same time. The answers to all these questions are disputed. During the 20th century, the comparison of Stalinism and Nazism was made on the topics of totalitarianism, ideology, and personality. Both regimes were seen in contrast to the liberal West, with an emphasis on the similarities between the two, while their differences from each other were minimized.Hannah Arendt, Carl Friedrich and Zbigniew Brzezinski were prominent advocates of this "totalitarian" interpretation. The totalitarian model was challenged in the 1970s by political scientists who sought to understand the Soviet Union in terms of modernization, and by the functionalist historians, Martin Broszat and Hans Mommsen, who argued that the Nazi regime was far too disorganized to be considered totalitarian. The comparison of Stalinism and Nazism, which was conducted on a theoretical basis by political scientists during the Cold War, is now approached on the basis of empirical research, now that greater information is available. However it remains a neglected field of academic study.