With the end of the Cold War and the collapse of the Soviet Union, the U.S became the world's only "hyper power". A state defined as possessing such overwhelming economic, technological, political, and military powers and resources, it has no rivals. No individual state, nor any alliance of states are capable of challenging its global primacy. Washington can project its power anywhere across the globe at any time. Power so intimidating, it should fulfill the maxim of Sun Tzu, China's great military strategist: "The supreme art of war is to subdue the enemy without fighting." Power that has, however, experienced unanticipated limitations, writes Joseph E Fallon.