I guess in a formal legal sense Schäuble is right. This is the problem with international contracts. It binds the government no matter what the electorate says. I think this is the reason why free trade deals are seen as so important. Free trade contract forever enshrine neo-liberal economic principles.

But look, not to beat a dead horse here. But many rules have been broken already. The ECB is not keeping its mandate and it is Germanys fault.