In February 2003, John Brady Kiesling publicly resigned his position as political counselor of the U.S. Embassy in Athens to protest the Bush administration’s impending invasion of Iraq. He was certain the security, economic, and moral costs of this war would far outweigh any benefit. Diplomacy Lessons is inspired by Kiesling’s conviction that disasters like Iraq are foreseeable and preventable. Kiesling calls for a more realistic foreign policy that recognizes the limits of U.S. power and the value of diplomacy.