The worldwide financial crisis of 2007-2010 was set off by the collapse of the subprime mortgage market in the U.S. This crisis caused widespread banking failure in the U.S. and forced the federal government to provide a massive bailout to the financial sector. The crisis simultaneously reverberated to banks around the world, and eventually brought about a worldwide recession. This paper documents why Western European countries were so susceptible to the housing price downturn. We explore various mechanisms by which the financial crisis might have spread including the existence of similar regulatory schemes, government deficits and current account imbalances, export connectedness, and the presence of a housing bubble. We present a surprising result: European banks went down because they had joined the market in the U.S. for mortgage backed securities and funded them by borrowing in the asset backed commercial paper market. They were pursuing the same strategies to make profit as the American banks, and when the housing market turned down, they suffered the same fate as their U.S. counterparts. Our study makes a broader theoretical point suggesting that subsequent studies of global finance and financial markets need to know something about the identities and strategies of the banks that structure the main markets for different products. This insight has implications for the literatures on financialization, globalization, and the sociology of finance.