Sebastian Junger was embedded with a US Army unit in the Korengal Valley in eastern Afghanistan for over a year. This book is the result of that experience.
It is an interesting mixture of styles: there is the "Despatches" School of blood, profanity and squaddie philosophy; then there is a technical discussion of how the US Army wages war on the Taliban; finally, an attempt to place the experience of the men in some kind of psychological and social context. Junger resists the temptation to go too far in any direction and the result is a good book.
The soldiers are not seen as quaint or odd but as functioning as well as they may with their lives to date and their present position. Junger gives a view as to why so many die so bravely (he discusses what bravery means) and so many of the survivors suffer yet re-enlist; reminding us that unlike Vietnam these are not conscripts. There is even time to consider the motivation of the Taliban as they sit out in the hills trying to ambush the Americans.
The men in the Korengal chronicled by Junger compare well to the GIs in Vietnam chronicled by other more excitable accounts; this group come over as being much more fluent in counter-insurgency and much less "deranged"; but that maybe a function of Junger's ability to not get in the way of their story. As an account of men under fire it is in the tradition of the Great War rather than Apocalypse Now.