For the reasons discussed previously, the United States presently is in a unique historical position. In the five centuries preceding 1991, no power attained unquestionable preeminence worldwide, but the United States presently has the world’s largest economy, easily the most powerful military, and Washington effectively acts as the chief arbiter of international affairs. It would be a considerable exaggeration to say that Washington rules the globe, but, to use Colin S. Gray’s metaphor, it is the international sheriff – a capable gunslinger and the only actor capable of organizing “posses” that maintain world order.84