I don't understand this argument. Are you claiming that there's no social safety nets in Europe? There are and have been and will still be without a federal government (although I like to argue we already have a defacto federal government).
Just because individual member states provide their own social security and finance it through borrowing money from the central bank(s), doesn't really seem that different from a federal government directly providing social safety nets. In fact, most member states have a way better social security net than United States. I could, in theory, just stop working today and get paid about $1200/month in addition to things like practically free health care and university education. Of course, there are poorer member states that have worse social security.