For over half a century the U.S. dollar has been the currency par excellence as it was the main vehicle for business transactions and financial affairs, both private and official level. The undisputed pre-eminence of the U.S. dollar has been the hallmark of international monetary relations throughout the second half of the twentieth century. The centrality of the dollar has survived unscathed the numerous imbalances and tensions that, in the past decades have marked the economic environment, financial and political world, and all the inevitable consequences occasioned in the monetary environment. The U.S. and European crisis, however, may have initiated a process of profound transformation of the international monetary system, characterized by the loss of the dollar as an international currency. The emergence of a credible alternative to the dollar in the role of an international currency, that these were the first of the sovereign debt crisis in Europe, are the factors likely to undermine the undisputed leadership of the dollar but also the reasons that make rethink the impossibility of a new monetary order the name Bretton Woods 2.