The whole European Union thing was a gambit by starry-eyed politicians who had succeeded, with the Single European Act, in establishing a complete single market with free movement of capital, goods, services and people.

The starry-eyed politicians came up with Schengen and the Euro and the Common Foreign and Security Policy and the Cooperation in Justice and Home Affairs, and voila, the European Economic Community became the "first pillar" of the European Union.

See wikipedia, as usual...

Economics is politics by other means