Talking to English friends recently, it has become apparent to me that they don't really think that the United Kingdom is in the process of breaking up as a result of Brexit. It will all blow over, they insist, when everyone realises what a great success Brexit is. Things will unfold like England after the Reformation - sure there were difficult times, some beheadings, a few burnings. Bloody Mary. But then it all came good under Elizabeth l. And that is how it will be again. But my perspective as a Scot is pretty clear. Brexit spells the end of the UK. Here's why:
1) Northern Ireland
Northern Ireland voted to remain in the European Union. So a UK-wide Brexit would mean that for the convenience of the English, Ireland and the European Union would be expected to undertake the trouble and expense of enforcing a border across 300 miles of the island of Ireland. Fuck that for a game of soldiers.
The better solution is for Northern Ireland to remain in the European Union, which it voted to do, and the border of non-EU land to be on the British mainland. This would effectively create a united Ireland, though sovereignty could be shared between London and Dublin.
2) Scotland
Scotland also voted to remain in the European Union. The Scottish government asked the government in London for a flexible approach to Brexit which would allow Scotland to remain in the EU but that was rejected. A consequent vote of the Scottish Parliament for a new independence referendum has been stalled; PM Theresa May says "Now is not the time" and won't discuss a date.
Scotland is not Catalonia: it was joined to England in 1707 by the Treaty of Union which was voted on by the Scottish Parliament. It has had centuries of nationhood, with a system of government, its own law, its own Church. The British royal family acceded to the throne through its connection to the unbroken 1000-year line of Stuart kings of Scotland. Scotland has a devolved Parliament which has voted for a referendum. If stonewalling by London continues, Edinburgh may well have a legal and democratic case for calling a referendum on its own behalf which could lead to a unilateral declaration of independence.
One thing is certain, the Scottish Parliament is unlikely to accede indefinitely to London's requests to put a (sweaty) sock in it.
3) Gibraltar
Gibraltar also voted - almost to a man and woman - to remain in the European Union. Until Spain joined the EU in 1985, there was a gated border on the rock, but Spain opened this under the freedom of movement rules within the European Union. Since then, there has been free movement across the border. But If Gibralter leaves the EU as part of the UK, the bilateral conflict with Spain over its sovereignty obviously re-emerges. The border could end up being closed again. English politicians' sabre-rattling over this recently was an example of how dangerous this could be.
It makes much more sense for Gibraltar to remain in the EU. Potentially, of course Gibralter could be managed by an independent Scotland which remains an EU member. Incidentally, Spain has recently withdrawn a previous threat to veto Scottish membership of the EU.