The question of Ireland, and trade across the intra-Irish border, has become one of the most difficult issues in the Brexit negotiations. It is not only a knotty problem in itself, but is throwing a revealing light on attitudes in both the EU and the UK.
The UK’s negotiations with the EU-27 failed to progress as much as the UK hoped at the last joint meeting. This is partly a question of money – how much the UK is prepared to pay. But there are other factors at play here too.