The New Rules of War: Victory in the Age of Durable Disorder.

• Author: McFate, Sean
• Position: FURTHER READING

Sean McFate, a professor at National Defense University and Georgetown University's School of Foreign Service, in his new book outlines 10 new principles of war.

The former Army paratrooper states that "conventional war is dead." Only the United States prepares for conventional war, "which is why we lose," he writes. "We must re-tool our military to fight post-conventional wars, and that means dramatic change."

After his stint in the Army, McFate served as a gun-for-hire in African hotspots and argues that mercenaries--once common and acceptable centuries ago--will be back in a big way even though they are looked down upon today. They are already serving nations in the...