Agree, Breck.
    In fact, the Red Army surpression of the revolts was the "very thorny cudgel" device the government could rely on, it accompanied the carrot. Again the "very thorny" emphasizes the regime meant business, it would give hard times to the discontent ones. As the book was  authored by an American writer, seems  that it have a scholarly bias to it (more so, with Harvard seal of approvation).

     I have learned that Mr. Service also "Fellow of the British Academy and Professor of Russian History at Oxford University".   
     So, having quickly scanned  at  http://www.hup.harvard.edu/catalog.php?isbn=9780674046993 so he might have a one-sided view of History.  In vocabulary for example, he could use ''carrot and stick'' to the Western countries and "carrot and very thorny cudges" to the eastern ones...for effect, I mean.

      Of course, I am not saying that he is wrong in doing so; but the reader have to know that behind any book or writting there are interests.

       PP.