In France they call it the “cordon sanitaire”, in Germany the “Brandmauer”, or firewall. Throughout Europe in the decades since the second world War the idea reflected a strong political consensus, from mainstream conservatives to the far left, that rejected collaboration with, and most definitely joining government with, the anti-democratic far-right, specifically that with a Nazi past or sympathies. Not any more. The EU had this week been preparing itself to welcome ministers from an Austrian far-right-led government until coalition talks in Vienna collapsed. Freedom Party demands over support for Russia, the EU and control over intelligence operations were a...