This is a global history of the Communist International from the perspective of its employees. This book got a lot of attention, at least for a German-language book about Communist history, and is currently being translated to English, Spanish, and Turkish.
The publicity made it sound the focus would be on the "proletariat" of the Comintern — the typists, smugglers, etc. — whose stories were newly rescued from the archives. In fact, the main protagonists are quite well-known activists such as M.N. Roy, Evelyn Trent-Roy, Willi Münzenberg, Babette Groß, Heinz Neumann, Margarete Buber-Neumann, Karl Gröhl / Retzlaw, Jules Humbert-Droz, etc. — if not the top-tier leadership, then the second tier. This book is largely based on published memoirs and biographies, and supplemented by documents from the Comintern archives.
Even if you're a Comintern nerd who has read all these stories, Brigitte Studer nonetheless weaves them together to shows how they converged at different "hotspots" of Communist activity: Moscow 1920, Berlin 1923, Shanghai 1925-27, Madrid 1936, etc. Where Studer has lots of new information is on Swiss Communism, and also on the Comintern's secret apparatus in Shanghai, which had a complex connection to Switzerland. She also shows how women were doubly excluded, both from revolutionary praxis and from the history of revolutionary praxis — condemned to being known only as the partner of so-and-so, even if they were important leaders in their own right.
What this books lacks, unfortunately, is a coherent theory of Stalinization. The radical zigzags in Comintern policy (from anti-colonialism to support for "democratic" colonial powers, for example) are presented as a gradual, Weberian process of institutionalization and professionalization — the murderous bureaucracy was a "Human Resources Department of a special kind." Thus, the book lacks much insight on revolutionary lessons from the Comintern experience. I am really looking forward to the English translation of Pierre Broué's History of the Communist International, which is going to appear in the not-too-distant future.
Finally, why does every new history book need a 50-page introduction about methodology? If you like to watch soccer, do you want to be forced to watch a 30-minute interview with the team nutritionist before every game to learn what players are eating? I think these introductions are pretentious, repetitive, and so, so, so boring. Every single historian is supposed to have discovered some totally new way to write a book? If people need to write essays about their theory of history, I suggest that these be published in a special journal. Then we can put all copies of the journal in a shed and then burn the shed down. This would save so much paper. If you have a unique way to write a history book, then show me, don't tell me. Academia really poisons everything, huh? As a historian, I am going to go out on a limb and say: books, and especially their first chapters, should be interesting, not boring.