Today's tensions are rooted in paralysis on global rebalancing. Over-spending countries - such as the United States and other "Anglo-Saxon" economies - that were over-leveraged and running current-account deficits now must save more and spend less on domestic demand. To maintain growth, they need a nominal and real depreciation of their currency to reduce their trade deficits. But over-saving countries - such as China, Japan, and Germany - that were running current-account surpluses are resisting their currencies' nominal appreciation. A higher exchange rate would reduce their current-account surpluses, because they are unable or unwilling to reduce their savings and sustain growth through higher spending on domestic consumption.
Within the eurozone, this problem is exacerbated by the fact that Germany, with its large surpluses, can live with a stronger euro, whereas the PIIGS (Portugal, Ireland, Italy, Greece, and Spain) cannot. On the contrary, with their large external deficits, the PIIGS need a sharp depreciation to restore growth as they implement painful fiscal and other structural reforms.
