Problem is we view the EU as a friend. Europe has a long history of being uncomfortable with any power greater then them. When Britain became powerful, Germany and France ganged up on her, when France became powerful, Britain and Germany ganged up on her and the same happened to Germany. France, Germany and Britain has gotten over this but they will not hesitate to act in concert against any power greater then them, and in this case it is the United States, the sole super power after the Cold War. The EU cannot use military power because they do not have any, but they will use soft power to rein in and manipulate the US. They like to form international organizations, pass international rules and regs to undermind US economic might and attempt to force us to abide by them by using their media and academic inroads into our society to create public pressure on our officials. The international court, global warming, political correctness and a number of our current political hangups and self imposed limits originated from the leftist Europeons imported into our academia, media, the Democratic Party and even to our globalist corporate elites and legal thinkers. Net effect is a super power with great military power limited by a confused and self imposed guilt to act effectively. The EU is our worst enemy because unlike the Russians and Chinese who oppose us in a naked way (military weapons and exercises) the EU appeals to us on common ground (same culture, racial makeup, historical ties, etc, etc, etc) but at the same time will plot and plunge a dagger into our backs. Old Sicilian saying - your enemies always oppose you, but only a friend can betray you.
I believe that France has been the prime mover and it was France who seized the first opportunity and virtually forced a common currency on the EU. One prize would be a currency that would be much stronger than the lowly Franc to combat the Dollar.
"The idea of adopting a common currency in Europe has long been a mythical objective, one that you talk about but never take seriously. It suddenly emerged as a very real possibility in the aftermath of the Soviet Union collapse. France was concerned that Germany would divert its attention to the East and Germany formally needed the Allies, including France, to agree to its re-unification with East Germany. President Mitterrand linked his support to the establishment of a common currency and Chancellor Kohl accepted the deal."
"European Monetary Union: the dark sides of a major success," Charles Wyplosz
A major question is can the European Monetary Union (the Euro) survive without closer political union among EU members. So far the EMU has not been severely tested but that test has just arrived.