Michael A. Levi is the David M. Rubenstein senior fellow for energy and the environment at the Council on Foreign Relations, where he is director of the CFR program on energy security and climate change. He is also adjunct assistant professor of international and public affairs at Columbia University, New York, USA. Michael E. O'Hanlon is a senior fellow in Foreign Policy Studies at the Brookings Institution, Washington, D.C, USA, where he holds the Sydney Stein Jr. Chair. His recent books include Neither Star Wars nor Sanctuary (Brookings, 2004) and Crisis on the Korean Peninsula (McGraw Hill, 2003; with Mike Mochizuki).