Brexit sees nationalism once again wind up unionism amid sham border fight
There has been a sham fight over the border since June 2016. The UK exercised an EU treaty right (article 50) to leave the EU. The ROI - with little internal debate - exercised the same right to remain a EU member state.
The UK does not want to put anything on the border. The ROI knows that - as a good EU member - it would have to impose the common customs tariff (the external trade frontier of the EU27). The sham fight has been Dublin trying to blame London, and the UK trying to manage Irish demands.
There is nothing inherently constitutionally threatening about "continuing regulatory alignment", the phrase yesterday which prevented a Brussels agreement.
One can have civil society continuing regulatory alignment, with a company or industry maintaining the standards demanded by the EU in order to continue exporting there. One can also have a NI continuing regulatory alignment, where Stormont (if returned) would have such a devolved power.
The DUP, however, has reacted to the idea of an east-west border down the Irish Sea, and sought to assert the continuing integrity of the UK. Nationalism once again wound up unionism.
Personally, I blame the British drafters in Brussels. They have always underestimated ideology when trying to deal with Irish questions. We know the UK is coming out of the internal market; it wants an association with the customs union; and Dublin will be compelled by Brussels to do its share of maintaining the protectionist bloc called the EU.
Austen Morgan is a barrister and the author of a legal textbook on the Belfast agreement