One thing Mr Clegg did get right in his speech to Chatham House yesterday was to question how much longer our approach will prove tenable. So far, it’s been grudgingly tolerated, if only because Europe has got rather bigger problems on its plate than its relationship with Britain. There is a sense in which the UK is slipping under the radar. Nor has this manoeuvring been without its successes. Britain has opted out of 130 directives concerning home affairs and justice, and it’s also managed to wriggle out of participation in future eurozone bailouts. What’s more, it has ensured that the fiscal compact applies only to members of the single currency. But the big prizes on employment law, human rights and so on have yet to be won. It is by no means clear that these things are deliverable under the present framework.