"Duty" by SecDef Robert Gates.
What I found very interesting is his evaluation of the US Military's Readiness Posture when he took office as SecDef.....and the situation it is in today. It seems those concerns then are the same concerns now.
His account of Military Leadership and Decision making at the Top Levels of the US Military are not very comforting. Having studied the Leadership in place during the Vietnam War years....I don't see much difference between then and now sadly.