Forty years of institutional arrangements and cross-border connections must be unravelled, whether the British exit from the European Union is smoothly negotiated or leads to the economic and social disaster forecast by naysayers including the European Commission (EC) and many of the 48.1% of British voters who voted Remain. The vote was an unpleasant surprise for many British and European establishment politicians and stunned many international partners, more used to the UK living up to its reputation for pragmatism and tolerance.