In the last few weeks, the idea of establishing a European banking union has become the latest remedy advanced as a solution to the long-running euro crisis. But whatever the merits of a banking union — and there are many — proposals to establish one raise more questions than can currently be answered.

The motivations of those who advocate a banking union differ markedly. For some, particularly in southern Europe, it is seen as a means of shifting the burden of supporting their indigent banks to those with deeper pockets. For others, especially in the European Union's Brussels eurocracy, it is seen as another leap forward in the construction of a European super-state.

Taking their cue from the sacred Rome Treaty's reference to "ever closer union," the European Commission's theologians view every crisis as an opportunity to advance their federalist agenda.