There was a series about Russia on Radio 4 last year (Russia: The Wild East by Martin Sixsmith). I only caught a few episodes at the time but I liked the sound of it. I was given the CD set for Christmas this year and it lived up to my expectations. So much so that it has inspired me to dig out all the books I bought when I studied Russian history.
This one is a fairly slim volume, a concise transcript from a series of lectures which Pipes gave in 1995. It identifies three key questions: Why did Tsarism fall; why did the Bolsheviks triumph and why did Stalin succeed Lenin? All three are contentious issues which have been debated for almost a century and there are many interpretations of the historical facts which are available (and there are, of course, many which are still restricted). This book gives an overview of the differing points of view but the author also gives his own answers to the questions he poses.
Yet the key question still remains: was Stalin an unfortunate accident or was Lenin heading in the same direction? It still has not been definitively answered.