"In 1949 the United States held three-Quarters of the world’s gold; by 1960 it had become a debtor nation. And yet, the United States has built history’s most powerful and affluent empire. Its techniques for world domination remained, at first, the conventional devices of the economic superstate. In recent years, however, the United States has sophisticated its strategy to the point here, although fallen into serious debt, it has retained and even expanded its dominance. The United States has pioneered a new form of imperialism in which the assets of its competitors have been employed for American ends. The or now calls the tune for the creditor."

http://parmenides2013.blogspot.it/2013/09/super-imperialism-economic-strategy-of.html