Ongoing events in Iraq show how difficult it is for the world's only remaining superpower to impose its will upon other peoples. From Vietnam, French and US, to Afghanistan, Russian and US, to Israel and the Palestinians, to Somalia and Kosovo, recent history is replete with powerful military forces being tied up by seemingly weaker opponents. Answers to the "hows" of this along with recommendations for prescriptive actions are found in Thomas Hammes insightful book on the strengths and weaknesses of conventional military power. Hammes, a full colonel on active duty in the Marine Corps is an expert at asymmetrical warfare, perhaps better known as fourth generation warfare (4GW). This is the means by which Davids can defeat Goliaths. Colonel Hammes is well placed to write this study. As a career-Marine he has trained 4GW warriors in some places and fought against them in others. He has also made a lifelong study of military history which helps him illuminate the previous three generations of armed conflict and define and detail the newest, fourth generation of war.