Why is the United Kingdom still a united kingdom?

The current PM is also a Scot. :) Born in Edinburgh and going to Fettes college is less Scottish that someone from Fife who went to Kirkcaldy High School. Unless it's St Andrew's in Fife. Have you seen the wall around Fettes? That's to stop the bagpipe-playing and kilt-wearing that goes on outside infecting anyone.

As does Canada, Australia, New Zealand, and the Irish Free State (until 1949). Not to mention over a dozen other Commonwealth Realms. That answer, while alluringly simple, doesn't actually qualify very much. And we don't even get to go into the short line at Heathrow! 200+ years of loyalty to the Crown, and we get diddlysquat. Lots of people from countries who have fought wars with Britain in the last century get to go to the quick European line, but her oldest and truest allies? The people whose ancestors fought in both World Wars (from the beginning) and who died in high proportions on a foreign continent to defend Britain -- we have line up with rebels like the Americans. / grumble, grumble, I hate what the EU has done to the Commonwealth, grumble

Nevertheless, devolution of authority to semi-autonomous regions seems to be a growing trend, as we've seen in the U.K., Spain, and Canada. posted by Midnight Creeper at 8:19 PM on May 14 [+] [!] Canada's current situation isn't really devolution, so much as never fully together, there was no de-volving to happen. The provinces were mostly independent before joining Canada, and kept many of their powers at confederation. Lower Canada (Quebec) and Upper Canada (Ontario) were joined briefly, but most of their history before 1867 was still separate. We're more centralised than the US, but still more decentralised than Britain. And to be nitpicky on meehawl (whose comments I do always enjoy) -- As you noted, the current United Kingdom of Great Britain and Northern Ireland was created in 1921, replacing the United Kingdom of Great Britain and Ireland which had been created in 1801. Prior to that, however, Britain was simply the Kingdom of Great Britain, and there was no "United" bit, though the crown also held the Kingdom of Ireland as a separate country. Great Britain itself was not created until 1707, when the countries of Scotland and England joined in the Act of Union. In 1603, the English and Scottish crowns had been united in one man - James I or VI - but the thrones weren't united at all. They continued to be separate countries, with separate parliaments, separate international and military agendas. Scotland declared war on Charles I, for instance, before England, and made peace with him earlier too (thus the invasion by the English under the Parliament). They were officially no more joined than Britain and Canada are today (since they also share a head of state); unofficially, the head of state in the 17th century was much more directly powerful, and so the two countries were quite "united" by virtue of having the same king (also republican England had conquered Scotland in the Civil Wars, but independence was restored in 1660, so that was a blip). The two countries decided they wanted to get properly United in 1707, because (basically) the English were afraid the Scots would go for a Stuart on the throne instead of a Hanoverian (possibly leading to war), and the Scots wanted access to the increasingly lucrative English Colonies (after their own failed miserably). So England got stability, and Scotland got in on the (now) British Empire. Before 1603, Elizabeth had ruled two kingdoms -- the Kingdom of England (with Wales as previously annexed principality) and the Kingdom of Ireland, while her cousin James ruled Scotland - and again, England and Ireland were separate countries, which just happened to be ruled by the same person, and the people chosen by that crown (which could be the same people, but Ireland still had its own parliament until 1800). All this stuff - whether countries were officially united or not - did matter, even when they had the same ruler, because it meant that they had local parliaments (or, in the case of Wales, was a personal fiefdom of the king with no parliamentary consent to law), local laws, adminstration, etc, and there was no central government over all of them, except in the person of the monarch.

Because a lot of my ancestors died to make it that way, and I'll be damned if I'm going to let a bunch of whinging Scots vote their way out of it! Or at least, that's what my Granddad would say.

Because the power of the political elite would be much diminished. I'm sure that you will have noticed that the UK government likes to play Tonto to the US's Lone Ranger, riding around the world righting wrongs. I think our credibility in this role is stretched as it is and it would only get worse should the country split up. Similarly, we trade on the size of our economy and particularly the financial markets. Again, the break-up of the UK would likely lessen these. All of this would lead to a reduction in the reflected glory for the politicos to bask in. Consequently, central government has spread a lot of FUD regarding dissolution, and the populace is therefore unsure of the desirability of this option. Also, as modernnomad points out, big business does not like uncertainty, and we all know who sets the policy agenda, right...........?

All have the same Monarch. As does Canada, Australia, New Zealand, and the Irish Free State (until 1949). Not to mention over a dozen other http://en.wikipedia.org/wiki/Commonwealth_Realms. That answer, while alluringly simple, doesn't actually qualify very much. We haven't even got into a discussion here, yet, of what exactly defines "http://en.wikipedia.org/wiki/British_nationality_law". You could be a British Citizen, a Citizen of the United Kingdom and Colonies, a British Overseas Territories Citizen, a British Overseas Citizen, a British Subject, a British National (Overseas), or a British Protected Person. A post-secession Scotland would presumably enable its citizens to obtain one or more of these "British" categories, or create an entirely new one. For instance, my grandmother, born in southern Ireland while it was part of the UK can still claim to be a "British Citizen". My father, born in the Irish Free State, can still claim to be a "British Subject". Is there a country with a more byzantine system of nationality and citizenship than the UK? I doubt it.

Um, great answers but they all seem to be missing the point. All have the same Monarch.

Given the number of senior Scottish Labour MPs, I also find it unlikely that Labour could support disunion between England and Scotland in the forseeable future. In such an arrangement, were the newly independent Scottish MPs not to take seats in Westminster, the Conservative (and ?Unionist?) Party would gain a much improved plurality in the newer, smaller Westminster government (given that its base tends towards the south-eastern portion of the island of Great Britain). It seems almost ironic, then, that that party which would stand to gain the most strategically from disunion is the Tories, who are historically opposed to such a development.

Scotland, Northern Ireland, and Whales also benefit economically from being a part of the UK. The English economy and industry is more self sufficient than the other constituents. The extent to which the other three countries rely on England is a point of debate, which is why the SNP has supporters and opponents.