The Devaluation of "America" the Brand
When people don't like you, they don't like to give you money. The charts below show a remarkably correlation between a country's view of the United States and its currency's exchange rate with the U.S. Dollar. Over the past seven years, the citizens of the United Kingdom, Continental Europe, and Japan have all experienced a marked decrease in their opinion of the U.S., along with a corresponding decrease in the U.S. Dollar's value against their respective currencies. Russians have maintained a pretty stable view of the United States, and the Ruble has maintained a relatively stable in comparison to the U.S. Dollar. Unfortunately China's currency is pegged by its government so we can not test this theory with its currency.
While clearly there are many factors that define an exchange rate such as a country's inflation and growth rate, at the end of the day a currency's value relative to another is defined by how much each country buys from each other. When Europeans by less American goods, services, and financial instruments than we buy from them, their currency raises in value relative to the dollar. Even though American goods end up costing less, less of them are bought.
When Nikes symbolize more than Michael Jordan but a country that someone doesn't like, they just buy a pair of Adidas sneakers. Brand devaluation generally builds as a wave, where people's perception gradually starts to affect their buying behavior. This is something that needs to be reveresed - the devaluation of "America" the brand will cost U.S. businesses a tremendous amount of money, far more than the economic impact of the Kyoto protocols or the cost of the Iraq war.
Data is from the Pew Global Attitudes Report and OANDA Currency History.