It's the divorce settlement from hell. With no pre-nuptial agreement in place, exactly how would Scotland withdraw from the UK, asks Chris Bowlby.
With the Scottish National Party in power in the Edinburgh devolved parliament, talk of independence is back on the agenda. Some remain sceptical that Scottish voters would back such a plan, but the SNP believes it will happen within a decade.
From carving up the family property to whose head appears on Scottish stamps, how might it work?
DIVIDING UP THE FAMILY PROPERTY
Oil matters hugely to Scottish nationalists, and most experts assume that, with the North Sea oil fields in Scottish waters, Scotland would get up to 95% of UK oil reserves, and nearer half of the gas. Natural resources would stay where they lie, but all other property is usually divided in these circumstances - as it was when the Czech Republic and Slovakia split in 1992 - according to population share.
That would mean Scotland laying claim to 8 or 9% of all the UK's assets, but valuable shared institutions - such as the security services - are physically sited almost exclusively in England. Most of the UK's wealth can't simply be carted off north of the border so a compensation deal would need to be thrashed out.
Moveable property would need allocating. The Czechs and Slovaks haggled over everything from state airline aircraft to works of art to the contents of every Czechoslovak embassy abroad. What would be Scotland's share of, say, the prestigious British embassy buildings and furnishings in Paris or Washington? And the BBC?
Scots would worry anxiously about the share they would inherit of the British national debt
But the UK has debts as well as assets. Scots would worry anxiously about the share they would inherit of the British national debt, including National Savings. If savers start worrying about all that and removing their money, that could make Northern Rock seem like "a walk in the park" says Peter Jones, co-author of Scottish Independence - a Practical Guide.
And state pension liabilities might be an especially tricky longer term issue tied up with citizenship - what happens to Scots who have migrated south in search of work and then return to live in Scotland?
The land border between Scotland and the rest of the UK is generally not in dispute. And given existing international commitments to free trade and movement, no-one is expecting regular border controls at Berwick or Gretna Green unless relations go badly wrong or a security threat emerges.
Scots would have their own passports but probably follow a common European format.
Maritime borders would be more sensitive given mineral reserves and fisheries, with the new Scottish navy likely to police carefully Scottish waters.
Scottish nationalists plan a modest Scottish Defence Force focused on peacekeeping. So Scots currently serving in the British army would have to decide whether to transfer. Scotland would also be entitled to a percentage share of military equipment as part of UK assets.
But by far the thorniest issue - probably in the whole negotiation of Scottish independence - would be the future of the British nuclear deterrent based at Faslane near Glasgow. The SNP has long campaigned to remove the Trident-equipped submarines from Scotland but "Whitehall would be deeply alarmed by that prospect," says Oxford University military expert Hew Strachan, "because there is no immediate place to take the deterrent to".
Although there has been a republican strain in Scottish nationalist thinking, the SNP is now committed to having the Queen as head of state of an independent Scotland, reviving the monarchical union with England that existed before the Act of Union in 1707.
So the Queen would still reside at Holyrood and Balmoral, but as Queen of Scotland. Her role might be defined in a different way as Scotland draws up its own constitution. And there would need to be agreement with what remains of the UK as to how to handle issues such as the royal succession.
In some ways Scotland's separation would not be as immediately visible as many might assume. The saltire already flies prominently in devolved Scotland, but would now no longer fly next to the union flag. And the fact that the Queen would still be head of state would presumably keep her image prominent on any new Scottish stamps.
As the SNP has opted to stay linked to sterling initially after independence, rather than create its own currency, existing Scottish notes could remain in circulation. And Scotland has long had its own football and rugby teams to cheer, though it would be fielding its own team at the Olympics.
What would be immediately visible would be the end of the UK presence abroad. Scotland would have to decide how far it wanted its own representation around the world, or whether it could continue to co-operate with what remains of the UK.
What was Britain's presence at the EU and UN, would have to be renegotiated.
Those challenging Britain's right to a permanent UN Security Council seat might choose the end of the UK as a moment to act. The EU position - how Scotland and what remains of the UK would replace the current UK presence - is complex and uncertain as there's no clear precedent. Some in the SNP think Scotland could even opt not to join the EU but make its own individual agreements with Brussels like Norway.
Analysis: The Beginner's Guide to Separation is on Radio 4 at 2030GMT on Thursday 6 December and Sunday 9 December at 2130 GMT. Listen online or get the podcast from the Analysis website
Below is a selection of your comments.
The SNP needs only to look at the Balkans to see where pseudo-nationalism and personal ego has taken those countries. We may not settle the dissolution of the union with AK47's and tanks, but it would nevertheless be as painful and as bitter. The rights and wrongs of the Union can be argued for ever, but would we be any better separate, viewing each other suspiciously over a porous and irrelevant border...?
Mick Ware, Marlborough
This is a very good piece which begins to bring home the reality of what the SNP proposes as opposed to the "Braveheart" stuff. Like many Scots people, I live in England. My wife is English. My children regard themselves as English. Personally, I do not regard Scotland as a separate country and I can't understand how Scots might think they are "repressed". There is so much held in common between Scotland and the rest of the UK. But what this does show that, contrary to the Nationalists propaganda, the rest of the UK DOES have a political and economic interest in the outcome of any Scottish "yes" vote. I don't accept the Czech/Slovak model as necessarily applying to the UK, and has anyone asked HM whether she or her successors are actually prepared to work with the SNP?
Barry Hamilton, Romford, UK
I am English. Alex Salmond is doing us a wonderful favour by taking Scotland "private ". The Act of Union 1707 is totally obsolete.
Bert Leech, Bedford
I would sooner emigrate than live in an independent Scotland. We are a small nation pretending to be a 'big boy'. I find nothing wrong with being a proud Scot as part of a United Kingdom.
The Queen would be Queen of Scots, not Queen of Scotland.
But I won't be voting for independence anyway, nor will most of my countrymen. Let Salmond chunter on about it, it won't change my mind!
We shouldn't even be talking about a separation! It's fuelling the fire. The article above shows how traumatic a break up would be for both parties, ruining tradition and world influence, potentially causing huge disputes over many things too for years on end. The advantages for the Scottish government pale into insignificance compared to the disruption for the whole population of Britain. The SNP are power hungry. Surely we can't let that ruin such a strong relationship?
Liam Houghton, Warwick
As a Scot I'm now 100% in favour of independence. This wasn't always my opinion, but as time goes by I'm more and more convinced it's the best possible option for Scotland.
B Sykes, London
Splitting the union would be a disaster for all concerned. Together we are a great power both within Europe and the wider world, separate we are easy pickings. The separate characteristics of the four peoples make a good whole too. The Intelligence of the Scots, the Courage of the Irish, the Cunning of the English and the Sheer Bloody-mindedness of the Welsh combine to make a great people. The only people to benefit from the splitting of the union will be the politicians as they will have even more power than they do now. The people of all four nations should put all our efforts to counter it.
As with any split brought about by one party, Scotland will want all the benefits and none of the responsibilities. I look forward to the debate and the international debacle as the UK breaks up at the whim of a hardcore group of Scottish Nationalist who can barely organise the parliament they have let alone one with real power and responsibility. The only plus I can really see is that our Prime minister will have to decide where his loyalties lie and get a UK constituency - if we have to keep him.
Peter Craig, Frimley
I'm not sure that the border would be unaffected by independence. Scottish membership of the EU would not be automatic - in all probability it would cease once Scotland stopped being a part of the United Kingdom and the Scots would have to re-apply. Until such time as it was re-admitted to the EU (as a country in its own right) border controls between England and Scotland would have to be maintained.
Philip Hulme, Stockport
What an incredibly biased piece of journalism. A break up of the UK would be like Serbia & Croatia? What laughable scaremongering nonsense. After that, is there any point reading the rest of the piece, or giving the opinion expressed any credence. I'm a Scot living in England, and would be delighted to see an independent Scotland. England pays no regard whatsoever to anything north of the border, so what are they so scared about that they must continually tell us what is best for us with these scre stories? Could it be that the ones to suffer would be England?
Surely there is a model for this divorce already. Up until 1922 the Republic of Ireland was part of the United Kingdom of Great Britain and Ireland. The divorce there dealt with Strategic Naval Bases- Britain held onto them for 10 years. Other problems like common travel areas and pensions were also satisfactorily resolved. So go on Scotland use our blueprint. Although I would recommend you avoid the 70 years of economic troubles that followed independence.
If you look at the qualifying criteria set down by the Copenhagen Criteria for membership, Scotland would qualify to remain a member state of the EU. Personally I think that Scotland needs independence, too many times Scots have used their perceived repression by the English to play the role of victim. The truth of the fact is that is has served the purpose of the ruling politicians to maintain a status quo which benefits them and not those that they represent. Whilst not claiming that Alex Salmond is Scotland's Moses destined to lead his people to the promised land, he is the person who will at least ensure that Scottish self determination is at the fore front of Scottish/UK politics for the foreseeable future.
Andrew Penman, Newcastle