In a thriving world economy there has to be a bying as well as selling. Right now the US is doing a lot of buying which makes for more selling from elsewhere. If the dollar is steeply devalued there will be nobody ready to pick up the buying that the US can no longer afford. Europe wants to se a gradual shift from dollars towards euros so slow and continuous that other markets will devellop replacing the US. That way a recession can be avoided and more stability can be found.
"Because U.S. economic growth has been rapid in recent years, American consumers are snapping up foreign goods of all kinds -- autos, electronics and clothing being some of the biggest categories"
"...Chrysler automobiles, which were assembled at a Dailmer-Chrysler plant in Germany and imported for U.S. distribution, await shipment at the Port of Long Beach in Long Beach..."
http://www.washingtonpost.com/wp-dyn/content/article/2006/02/10/AR2006021000531.html