Over half a century after its original publication, "The Origins of Totalitarianism" is still the most important treatise on totalitarianism in government. Arendt's book is also just as relevant and important today as it was in the mid-20th Century.
The book is divided into three main sections: Antisemitism, Imperialism, and Totalitarianism. In the first section, Arendt tracks the rise of antisemitism in Europe, looking mainly at 19th Century events and situations that aided the spread of this phenomenon through European culture. The Dreyfus Affair, which sharply divided France and ultimately became a political battle between antisemites and their opponents at the end of the 19th Century, gets more attention than any other event in this chapter.
In the middle section on imperialism, Arendt shows how the rise and fall of the continental European imperialist movements of the 19th Century (mainly, Pan-Germanism and Pan-Slavism) helped set the stage for their 20th Century totalitarian successors. As she puts it in opening the chapter on "the Pan Movements": "Nazism and Bolshevism owe more to Pan-Germanism and Pan-Slavism (respectively) than to any other ideology or political movement. This is most evident in foreign politics, where the strategies of Nazi Germany and Soviet Russia have followed so closely the well-known programs of conquest outlined by the pan-movements before and during the first World War that totalitarian aims have frequently been mistaken for the pursuance of some permanent German or Russian interests. While neither Hitler nor Stalin has ever acknowledged his debt to imperialism in the development of his methods of rule, neither has hesitated to admit his indebtedness to the pan-movements' ideology or to imitate their slogans." It's a testament to the truth and prescience of Arendt's work that the preceding passage remains as timely as ever, given the ongoing collapse of the Pan-Arabist movement which dominated the Middle East during the second half of the 20th Century and the battle between democracy and totalitarian Islamofascism over which will rise up next.
The first two sections lead perfectly into the third and most important part of the book: the section on totalitarianism. Arendt shows how Nazism and Bolshevism were much more similar in their goals, practices, ideologies, and enemies than many people often believe or want to admit. They were both mass movements that sprang from cultures that had largely dismissed any objective truths. (Arendt: "The ideal subject of totalitarianism is not the convinced Nazi or the convinced Communist, but people for whom the distinction between fact and fiction and the distinction between true and false no longer exist.") Both movements sought power for the sake of power, were rigidly ideological, made widespread use of terror, sought not only to punish and kill their enemies (as many brutal governments before them had done) but to dehumanize them and erase any trace of their existence from the memories of the governments' other subjects, a phenomenon introduced to the world by these 20th Century totalitarian governments.
Many people have said in the decades since the Holocaust and the Soviet Gulag that the world should never let these atrocities happen again. But the sad irony is that many of these same people then promote a materialist, existentialist worldview that are the breeding grounds for the same radical totalitarian governments that ultimately carry out these atrocities. Arendt recognized this problem: "...We actually have nothing to fall back on in order to understand a phenomenon that nevertheless confronts us with its overpowering reality and breaks down all standards we know. There is only one thing that seems to be discernible: we may say that radical evil has emerged in connection with a system in which all men have become equally superfluous. The manipulators of this system believe in their own superfluousness as much as in that of all others, and the totalitarian murderers are all the more dangerous because they do not care if they themselves are alive or dead, if they ever lived or never were born... Totalitarian solutions may well survive the fall of totalitarian regimes in the form of strong temptations which will come up whenever it seems impossible to alleviate political, social, or economic misery in a manner worthy of man."
So where do we go from here? "Never again?" I'd love to think so, but I'm not betting on it. I don't think Hannah Arendt would either.