Tribe: On Homecoming and Belonging by Sebastian Junger is his take on the reasons so many of our returning military personnel have a difficult time readjusting to civilian life. His theory is fascinating--that we are missing that strong connectedness and sense of community that we used to have when humans were members of a tribe. War, which entails being intimately connected to and dependent on your fellow soldiers, actually provides the closeness that is often lacking in today’s society. Coming home from the bonds of war can be hugely discomfiting. It’s a very thought provoking book and he has done a lot of research into tribal bonds to bolster his theory.