How will the euro affect transatlantic relations? Even while partners in a political and military alliance, Europe and the United States have long been rivals in monetary affairs. Until recently, however, it was a rather one-sided contest, since Europe had no currency - not even the fabled Deutsche mark (DM) - that could effectively match the U.S. dollar as international money. Now Europe has the euro, which many have predicted will quickly emerge as a potent competitor to America's greenback. Could growing rivalry between the dollar and the euro endanger the historic European-American partnership?