Comrades by Robert Service
This book does a great job of tying together the diverse histories of communism(s) and communist movements from around the world, highlighting what they shared as well as where they diverged. Through examining communism in Soviet Russia, China, Vietnam, Cuba, Cambodia, etc. we can see what was essential to communism (its authoritarianism and totalitarianism) from its inessential. However this is not as gripping as Service’s book on Lenin, and in attempting to be a broad survey of world communism it becomes too shallow in its treatment of particular instances of communism – and yet it is in only in understanding the particular that we can fully understand the general. It certainly enhanced my understanding of communism – especially in conjunction with his biography of Lenin, but left me feeling unsatisfied.