For a decade America’s share of the global economy has been in decline.Its diplomatic alliances are under immense strain, and any claim of moral leadership has been abandoned.America is still a colossus, possessing half the world’s manufacturing capacity, nearly half its military forces, and a formidable system of global surveillance and covert operations.But even at its peak it may have been sowing the seeds of its own destruction. Is it realistic to rely on the global order established after World War II, or are we witnessing the changing of the guard, with China emerging as the world’s economic and military powerhouse?America clings to its superpower status, but for how much longer?