I CAN’T help noticing how the old, poisonous football enmities between Scotland and England have matured into a civilised banter, even respect. Meanwhile, the atmosphere on the political football ground, at Westminster, has coarsened beyond belief. Both sides are barely speaking to each other.

Tory MPs and their chums in the Westminster lobby are contemptuous of the tiresome SNP MPs and their “stunts”. Well they’ve seen nothing yet, as the Nationalists plan a campaign of parliamentary attrition based on the Irish Home Rule disruption. David Mundell, under pressure from a Brexit-or-bust cabinet, is refusing further concessions on the power-grab issue. In response, the Scottish Government is pledging a campaign of non-cooperation with the UK Government.

To be frank, there has been precious little cooperation for the last two years. The joint ministerial committees, which are supposed to thrash out issues between UK and Scottish departments, should be renamed the lapsed ministerial committees. It is not the consent issue alone though, as Professor Aileen McHarg argued in yesterday’s Herald, the UK Government can’t simply ignore the Sewel Convention. A Legislative Consent Motion is still a formal requirement of a UK Bill getting the Royal Assent. There are more consent deadlocks in the pipeline as the UK Government tries to push EU-related trade bills through Westminster this summer. Then there will be the Supreme Court ruling next month on Holyrood’s Continuity Bill, which seeks to retain repatriated EU laws. But these pale into insignificance compared with the rows ahead on Ireland and Barnett.

Northern Ireland is set to remain in regulatory alignment with the EU single market, post Brexit, under the “backstop” agreed by the UK Government in December. Brussels is holding Theresa May’s feet to the fire over this. It will be explosive in Scotland since two out of three Scots voted to Remain yet are being taken out of the EU single market without concessions.

But money will be the big one. As the Institute for Fiscal Studies has argued, the back-of-the-envelope Barnett Formula on Scottish public spending cannot survive Brexit. Huge rows lie ahead on issues such as farm payments, as well as on regulatory matters and fiscal transfers. In this toxic climate, barely-disguised hostility towards the Scots for getting more than their fair share of public spending will be inflamed. Lord Ashcroft’s latest polls suggest a large majority of Leave voters would be content to see the break-up of Britain, if that is the price of Brexit.

Countries can become independent almost by accident. Exactly 25 years ago the former Czechoslovakia split after circumstances not dissimilar to the UK’s today. The country was extricating itself not from the EU but the Warsaw Pact. Slovakia was seen as a troublesome encumbrance by the larger and (then) more prosperous Czech region. Slovaks were always complaining about “ Prague centralism”, demanding more than their “fair share” of public spending. The issues are uncannily familiar.

The Czechs wanted to go fast forward to a liberalised, free market future, while the “backward” Slovaks sought to go more slowly. They toyed with a federation, but no one’s heart was really in it. In the end, Vaclav Havel, the Czech Prime Minister and Vladimir Merciar of Slovakia decided, with regret, that a split was the only way. Votes in their parliaments declared the two republics to be independent. There was no referendum in 1993. Indeed, opinion polls after the split suggested fewer than 40% of Slovaks wanted independence; most wanted a kind of devo max.

But it worked because independence proved to be easier than anyone expected. State assets were split on a ratio of two to one. Slovakia was recognised by the World Bank and International Monetary Fund almost overnight and became a member of the United Nations in just 19 days. The new countries tried to remain in a currency union but that lasted only a few months.

Slovakia has rarely looked back. It regularly tops the EU growth league and is the world’s largest per capita car exporter. But this divorce was not all velvet. There was a good deal of pain before gain. Devaluation reduced the underlying value of assets and pensions in Slovakia. Unemployment spiked. Business was disrupted because the Czech Republic was, and remains, Slovakia’s biggest economic partner. The Slovaks kick-started growth by slashing taxes and social protections: shades of the SNP Growth Commission.

A significant minority in both countries still resent that they were not given a choice in a referendum. But many of the border issues were resolved by joint membership of the EU and Schengen. In a way, this reunited the old country, living apart together. Everyone agrees that old enmities and grievances were resolved by independence. When Mr Havel died in 2011, he was mourned equally by Slovaks and Czechs.

The comparison is inexact. Scotland is a much richer economy than landlocked Slovakia, which had no natural resources and little industry when it split. Scotland would not be able to emulate Slovakia’s “miracle” because Scotland is a mature economy with a large public sector. Also, the rest of the UK is bent on departing the EU, which would leave Scotland with a hard border between itself and its largest trading partner, England.

We should bear in mind how quickly relations can deteriorate between partners in a union, especially when the larger partner has other things on its mind. Brexit is a national crisis with a strong regional dimension. Most Scots are not content about being taken out of Europe. Many see their Parliament stripped of powers. They will rightly demand parity with Northern Ireland.

Mired in money and legal disputes with no solution, with Tory MPs and an English media contemptuous of Scotland’s refusal to join the Brexit project, the day may come when both sides recognise that things just can’t go on: a woollen divorce. It would be very British and probably not be called separation but the creation of a new UK of autonomous nations: Next UK?