"A serious political and social crisis will sweep through the euro countries if they do not decide to strengthen the integration of their economies. The euro zone crisis did not begin with the Greek crisis, but was manifested much earlier, when a monetary union was created without economic and fiscal union in the context of a financial sector drugged on debt and speculation.”
Three different models for regional unification have been proposed by the movement for European integration since its inception. One vision is a league of states that preserve national sovereignty while committing themselves to follow specific policies agreed by consensus.