If Greece leaves the euro, the U.S. economy could easily slip into recession. That cost is worth bearing, however, given the long term consequences of Europe struggling with a currency regime that makes little sense.
Essentially, Athens would exchange drachmas for euros in circulation among its inhabitants, remark private debts and bank accounts to drachma, and until conditions stabilized, limit withdrawals at Greek banks and capital outflows.
As the drachma fell in value, Greek exports would increase, reducing unemployment. consumers and businesses, with their debt redenominated into a cheaper currency, would enjoy a windfall and spend more. All would help lift the Greek economy out of crisis, but this can only happen if Germany and other European governments cooperate.
The money Greece owes other governments, the European Central Bank and International Monetary Fund—under international law—can only be remarked to drachma with their consent, but that debt is too substantial for Greece to repay in euro.
The disastrous consequences of German reparations after World War I should compel European leaders to accept payments in drachma. The accompanying losses are manageable, but concerns about contagion will require that capital controls and additional ECB support be immediately deployed to banks in Italy, Spain, Portugal, and perhaps Ireland.
Uncertainty breeds panic, and even with these thoughtful measures, the euro will continue depressed, and the overall European economy is not likely to grow for a year or two or may even contract by one or two percentage points.
Europe is an important market for U.S. exports and those will stagnate. As importantly, US banks and investors will take a hit from a further declining euro and reduced European bank lending activity in the United States and in countries that buy American products. Overall, expect U.S. growth to slow by 0.5 to 1 percent from the fallout of Greece leaving the euro.
By itself, that is not enough to sink the U.S. economy. Forecasters are predicting growth of about 2.5 percent for 2012 and 2013, but most have assumed the president and Congress reach some kind of compromise on the large federal spending cuts and tax increases that will trigger January 1.
Even if President Obama is reelected, he will likely still have a strongly Republican House.
Emboldened by their November triumphs, neither side will be in the mood to do much compromising, but they will find some creative way to kick the can. If Mr. Obama is a lame duck president, double that assessment, and Mr. Romney, constrained by the lack of 60 Republicans in the Senate, would not be able to accomplish much more immediately.
Business uncertainty in this climate make the 2.5 percent forecast unrealistic, and amid all this international and domestic turmoil, and a one percent hit to US GDP growth from a Greek exit from the euro could easily slow U.S. growth to less than one percent. That is too weak to be sustained, and a recession could easily result.
Still after a year or two, Europe would reemerge, and that would improve US long term prospects—a prosperous Europe is critical to American prospects.
The alternative in Europe is continued turmoil and stagnation, or long term contraction and decline, as it tries to make an unworkable currency regime work. The long term economic and security consequences for the United States are too negative to willingly accept.
The euro has failed, and time has long passed for Greece to bail out.
Sooner or later, Spain, Portugal and perhaps Italy and Ireland, will have to follow, but after the world does not end with Greek withdrawal, those would be easier and less painful decisions to manage.
The euro was a bad idea with the best intentions, and now the sensible course for all involved is to cut losses and return to the sanity of national currencies.