That most of the people objecting are American. Does the thought of Europe becoming one country threaten you that much? Not that it's anyone's business apart from the people living in those countries.
Yet their views on teamwork in the international community are hypocritical at best. (one can make an attempt to understand this if one looks at the power weilded by the americans and the general lack of education among the masses) Only in the liberal communities such as NYC or California will you find any support for greater global integration. The rest see any countries efforts at decreasing sovereignty as something to be avoided.