Hanson's book is a fantastic read. It includes vivid descriptions of several watershed battles in history and uses those stories to demonstrate his ultimate argument about why the West has always won out. Hansons argues that Western military hegemony is rooted in fundamental aspects of Western culture, such as consensual government and unfettered individualism. Contrary to racial, ethnic, geographical, or environmental explanations for Western military dominance, Hanson makes a strong argument for political freedom, capitalism, democracy, and scientific discovery being the determinants of success in battle. By examining the Battle of Salamis, the Battle of Gaugamela, the Battle of Poitiers, the Battle of Tenochitlan, the Battle of Lepanto, the Battle of Rorke's drift, the Battle of Midway, and the Tet Offensive, Hanson shows why each unique characteristic of Western culture is crucial to a positive outcome in battle.
As good of a read as the book may be, some of its incredibly strong claims simply don't hold up when examined more closely. That's not to say that Hanson isn't at least partially right, though.
Read the review in three parts: here, here, and here.