This is an interesting hypothesis on the coming tensions among rising powers over the next 100 years. although some major factors are glossed over or not covered at all. The author mentions that it is too hard to make predictions on such important factors as global warming and environmental change, and this takes away from his arguments. Overall, this reads more as challenges the US will face in the coming century. The author clearly shows that he has access to privileged information but states the big picture without going into great detail.