Junger's writing is always clear and concise. This book is enjoyable to read. In it, Junger convincingly argues that, counterintuitively, social cohesion is a positive outcome of war and that this confers positive mental health benefits on those affected. Personally, I found the most vivid parts of the book to be those concerning the bombings of London during World War II and his own experiences with PTSD in New York City's subway. And politically I agree with his plan for how best to accommodate soldiers returning from war: job placement and education. He argues that platitudes like "thank you for your service" only amplify the social disconnect between soldiers and civilians.
I did not enjoy the books lack of in-text citations and footnotes. He explains in the preface why he excluded them, arguing that they are distracting. And there is an appendix. But Junger presents many sweeping sociologic and psychological arguments that seem shaky without research. Junger's style in Tribe is the polar opposite of Sapulsky's in Behave where each minor assertion on human behavior is reinforced with half pages of footnotes on studies and reviews and exposition on the conflicts raging in academia. While Junger is not a psychologist or neurobiologist by training, I believe that he could have done something similar. The sacrifice to readibility would have been worth the added believability.
I recommend the book but am not convinced. Hopefully Tribe prompts more research.