This is a very detailed book written from the system point of view. The many details are set in the overall ideas of the political leaders and explain the effects of their interactions on the historical events. Among other political leaders Leon Trotski (born Lev Bronstein) ideas are included. It is very interesting - especially in view of Trotski being assassinated (1940 in Mexico) by the Soviet (Stalin) people.
Allocate enough time - the book is very detailed