This book is quite uneven, and does not fully live up to its promise - which does not mean it should not be read.
There are passages here on the psychology of totalization - and hence, of fascism - that are stunning in the clarity and brilliance. On the other hand, the author seems not to be able to sustain this level of analysis for more than a few pages at a time, before resorting to jargon, to his own use of neologism and other analytical contrivances, or to the diverting of attention to less urgent topics. In other words, while brilliant, this little work lacks discipline and maturity.
That said, students of these matters will profit enormously, especially from the discussions of purity and power in Ch. V, and from the general idea of revolutionary millenarianism which is, ultimately, Lifton's obsession.