By sticking with the Euro, Europe is saying that it wants to act like a unified bloc. However, trying to pursue a common economic policy while every member country pursues an independent foreign policy is, of course, a recipe for disaster. If Europe wants to act like a unified bloc, then it should really act like a unified bloc, and this means a unified foreign policy as well.
Europe needs to be more like the United States. Different ethnic regions in America seem to get along just fine without multiple foreign policies and a balance between federal and state control. Europe has too much local control with a single currency. Europe is trying to act like a single country with the Euro Zone, but it has failed on a policy level.
The Countries in the EU all have a varying degree of international influence and involvement. They deserve the right to make individual decisions that would effect their country in a positive way. Making group decisions would only lead to conflict. You couldn't tell Switzerland that it had to participate in an international conflict, that would go against what their government stands for,
We are starting to talk about nationalism. Everyone should have the ability to make their own choices. If they are all together not only do we loose individuality but we we never be able to decide anything because you are bringing so many people together from so many different backgrounds that they will never be able to decide what to do.