IT looks as if the choice may lie not so much between a soft Brexit and a hard Brexit as between a smooth Brexit and a rough Brexit – that is to say, between a Brexit that might leave much of life in the UK more or less intact and a Brexit that opens up hidden fissures or fractures likely to make for a jolting ride into an uncertain future.

The chance of a smooth Brexit has probably already been lost because the UK Government hatched no prior plans for it, and because the cabinet cannot even now, four months after the referendum, agree on what Brexit means. With Theresa May and her ministers hunkered down for an uncomfortable journey, she could hardly have expected her prattle about “our great Union” to cushion her encounter this week with the leaders of the devolved nations. Two of those leaders, Nicola Sturgeon and Martin McGuinness, do not think our Union is the least bit great. Evidently nothing in Monday’s meeting at Number 10 changed their minds, least of all the desperate rhetoric from May’s side.

She granted these leaders the empty concession that they can get in touch with Secretary of State for Brexit David Davis whenever they like. Would he otherwise have refused to talk to them? At least, however, the Prime Minister may have grown aware that she needs to give a little more elbow grease to maintaining the Union.

However, the Union has a long way to travel in this less-than-roadworthy condition. It scarcely helps that the driver is guided by a blind faith that the interests of the UK are identical with those of Leave voters, of which the overwhelming majority live in England. To those UK citizens who do not fall into this category, it comes across as bizarre that such interests should be regarded as of universal benefit. The Prime Minister insists the rest of us must espouse them too, even if we see in them a clash with our aims.

But this has ever been the British way. The latest phase of the UK’s economic history really started with the Big Bang of the 1980s: The deregulation of the City of London that opened its high road to becoming Europe’s pre-eminent financial centre. Since then, the rest of the economy has been consigned to the scrap-heap. All efforts to maintain at least some sort of balance with the previous manufacturing strengths were abandoned, as companies that actually made things went bust or slipped into foreign ownership.

It is a brave assumption, to say the least, that by the mere fact of Brexit this traditional economy can be brought back to life and thrive once again on trade with the rest of the world.

There is nothing in the recent performance of the UK to warrant such a view. Since the Big Bang its share of global manufactured exports has halved, and sunk to about the same level as that of Belgium, a nation of one-sixth the population. Performance has been especially poor in trade with Brazil, Russia, India and China – the countries supposed to offer the exciting new markets for British exporters to conquer. Some other recent increases in trade to them have amounted to 46 per cent for Germany, 35 per cent for Italy, 31 per cent for Japan, 24 per cent for France and 22 per cent for the US. The corresponding UK figure has been seven per cent – and this with a steady devaluation of the pound.

MATTERS have not been improved by the UK’s domestic economic policy over the same period, marked especially by efforts to boost house prices so that homeowners will feel richer and start spending again on the same reckless scale as in the early days of Tony Blair and Gordon Brown’s governments.

But people cannot be fooled a second time. And it is in fact better that way because a new spending spree could only suck in imports, not a good idea when Britain already has a trade deficit of about £100 billion, the biggest of the post-war period.

This British policy mix has been damaging to Scotland especially. A central feature at first was the manipulation of interest rates. But, as Scots have never really fallen for the boring obsession with house prices south of the border, this has only meant interest rates were kept higher than is good for the health of our own economy. A deflationary effect followed. Now that the UK no longer has interest rates, the Government in London has instead resorted to buy-to-let schemes and similar nonsenses to sustain its vital housing bubble. The effect is the same, only a bit weaker.

It is an excellent example of the error of Theresa May’s principle that the national interest – as defined by a Tory Government elected from England (where 318 of its 329 MPs have their seats) – is identical with the national interest of the other constituent parts of the UK. In the case of Brexit she goes further. Even for those other parts to raise questions of their own national interest in trying to establish a common position for the coming negotiations is, she says, to undermine the efforts of the British Government while it tries to get the best deal out of Europe.

No surprise, really, that a week of rapidly worsening relations between the central government of the UK and the devolved administrations has revived talk of federalism as the ultimate solution for our constitutional turmoil.

Federalism is regularly mentioned as a potential answer to Scotland’s constitutional debate. But could such a system work in the UK? Kezia Dugdale, Gordon Brown and Kenny MacAskill are just some of the politicians to raise the idea of Scotland gaining extensive powers while remaining part of the UK under a new federalist structure.

“Federalism offers a potential route forward for unionists to improve the constitutional settlement and for nationalists to maintain the dream,” MacAskill wrote in his column in The Herald this week. “Those who invoke and advocate federalism have an obligation to step forward and seek to help define it.”

Quite so, but I think those who do step forward will soon find themselves getting bogged down in problems for which there is no obvious answer, and perhaps no answer at all. Of the federal systems operating in the world, most seem to work well enough. But there is no such system in which one member state contains 83 per cent of the population, as England’s 53 million citizens would do in a UK federation of 64m citizens. What is more, those 53m show not the slightest interest in a federal system.

But there seems to me a still bigger question than the question of mechanism, daunting though this question is.

Still bigger than the question of mechanism is the question of mentality. If we look at the German federal system, for example, we see a constant process of give and take, and a willingness to compromise in a nation knowing it must never go off the rails again. Compare it to the mentality of Theresa May, which I think is also the mentality of English politics, and therefore of the rest of us whether we like it or not: Winner takes all. If we understand that, we see the Union can never be effectively reformed, only broken.