Europe is at a precipice, as voters across the continent have shown they are fed up with the existing political order and its prescription of austerity.

France's conservative government, led by Nicolas Sarkozy, was thrown out of power two weeks ago by Francois Hollande's left-leaning Socialist Party. Over the weekend, Angela Merkel's center-right Christian Democratic Union suffered its worst defeat in local elections since World War II. And Greece appears to be headed for a fresh general election, as its fractious political parties seem incapable of forming a coalition government.

For the first time, European leaders are even talking openly about a fissure in the continent's monetary union. Belgium's central-bank president told the Financial Times: "I guess an amicable divorce -- if that was ever needed -- would be possible, but I would still regret it." And his Irish counterpart echoed the sentiment: "Things can happen that are not imagined in the treaties … but [a Greek exit] can be managed. … It is not necessarily fatal, but it is not attractive."

For investors, the significance of such an eventuality cannot be overstated. If the monetary union fractures, an epidemic of currency devaluations will almost certainly ensue, causing American-made goods to increase in price on a relative basis, thereby driving down the continent's demand for them. More specifically, the following five American giants will be among those that feel the biggest impact, as they all look to Europe for a considerable portion of their sales.

Company

European Exposure (Percent of Net Sales)

Market Cap (Billions)

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McDonald's (NYSE: MCD) 40% $93 Add
Dow Chemical (NYSE: DOW) 36%* $38 Add
Nike (NYSE: NKE) 27% $50 Add
Ford (NYSE: F) 24% $40 Add
General Motors (NYSE: GM) 14% $34 Add

Sources: All geographic sales figures other than McDonald's and Nike's are from the respective companies' most recent quarterly reports. McDonald's and Nike's are from the companies' most recent annual report. Market cap data is from Yahoo! Finance.
*Includes sales to Europe, Middle East, and Africa.

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Fool contributor John Maxfield has no financial stake in any of the companies mentioned in this article. The Motley Fool owns shares of Ford. Motley Fool newsletter services have recommended buying shares of Ford, Nike, McDonald's, and General Motors, as well as creating a diagonal call position in Nike and a synthetic long position in Ford. The Motley Fool has a disclosure policy. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days.