<P>The last decade has seen not one but two energy revolutions. The first, explosive growth in demand from Asia's rising powers, fueled fears about scarcity and conflict. The second, an American revolution in technology and markets, is rapidly strengthening America's hand in the world. There are major security consequences of these shifts, from Saudi Arabia to Africa to Russia, and the emerging powers are increasingly exposed to them ?risks, as well as energy flows, are pivoting to Asia. All while a third revolution is struggling to be born, driven by climate change. Now, the United States faces a strategic choice. It has an enviable position in energy markets, and its naval presence at key chokepoints ?from the Persian Gulf to Southeast Asia ?gives it enormous potential leverage. But America will have to decide whether it wants to use energy as a stick, or to foster a more stable international system.</P>