Just a word of caution - Grossman has been criticized quite a bit, especially his earlier work On Killing. This is not to say that his work has no value, but it is in many ways based on false premises and oversimplifications.

In particular, his statistics regarding WWII and Vietnam have been shown to be very much off, thus undermining his central argument in "killology". Also, the idea of violence in PC games, TV and the like desensitizing the population or even teaching actual combat skills has been repeatedly disproven.

As far as military history, Grossman's view of combat is perhaps too limited to the modern Western world, failing to take into account the full extent of the individual's upbringing and cultural environment. Which is a bit strange since a number of military theorists since Clausewitz have placed considerable emphasis on that issue. Reader beware...