The divided country is not the UK but Scotland. Its divisions are cultural, geographical, religious, demographic and racial.
Demographically Scotland is a most peculiar place. It has a population estimated at 5.2 million in 2010 (http://www.scotland.org/facts/population/) set in an area of 30, 000 square miles (the UK is only 95, 000 square miles – http://www.nationsencyclopedia.com/economies/Europe/United-Kingdom.html) including hundreds of islands (http://www.scotlandinfo.eu/scotland-facts-figures). The overwhelming majority of the population live in the lowland belt not far from the border with England, with a mere 450,000 settled in the Highlands and Islands which cover around 60% of the area of Scotland (http://www.hie.co.uk/about-hie/about-hie/who-we-are.html). As such a dramatic physical division of people might suggest ,there are considerable differences between the highly urbanised lowlands and the sparsely populated highlands and islands. Scottish kings before the Act of Union in 1707 were generally kings of the entirety of Scotland in name rather than reality, the clan chiefs in the highlands and islands being effectively monarchs in their own domains. Until the second half of the 18th century the lowlanders considered the highlanders as primitives, viz: ‘The Highlanders said James VI summarily, in describing his own subjects for the enlightenment of his son, are ‘barbarous for the most part the islanders ‘utterly barbarous’ . A century later, the great Scottish patriot, Andrew Fletcher of Saltoun, looked upon them in the same way: to him they were the ‘wretched Highlanders’: few, worthless, and contemptible.’ (The Invention of Scotland Hugh Trevor-Roper p193).
The romantic myth of the highlander as the epitome of Scottishness developed from the middle of the 18th century, but at the same time as the myth was being constructed, the clan chiefs were organising the highland clearances of their own people, a process which continued well into the nineteenth century. This changed the highlands from, by the standards of the time, being well populated to a sparsely populated land, something which continues to this day. There is still a residue of resentment between those who consider themselves highlanders and lowlanders because of the clearances. The major inhabited isles are the Shetlands, Orkneys and the inner and outer Hebrides. All of these have a Norse history having come under Norwegian and Danish control in the ninth century. The Hebrides were ceded to Scotland by Norway in 1266 by the Treaty of Perth. The Shetland and Orkney Islands came to the Scottish crown in 1468 as payment in lieu of a dowry by the King of Denmark and Norway for the Norwegian princess Margaret ,who was betrothed to James III of Scotland. Despite attempts to get the islands back by Denmark they remained in Scottish hands. The Islands, especially the Orkney and Shetland Isles, still have a sense of being Norse rather than Scottish. There is also resentment at the treatment of the Islanders by the Scottish after control passed to Scotland. Here is a Shetlander Malachy Tallack writing in 2007: “ Denmark appealed to the[Scottish] crown [to get back ownership of the islands] several times over the ensuing centuries, but to no avail. Norse law was eventually ended in 1611, though Denmark has, in theory, never renounced its claim to the isles. Following the Act of Union between Scotland and England in 1707, at a time when many islanders still spoke the native Norn as their first language, the vast majority of Shetlanders were forced into serfdom. The people were cruelly exploited by their new Scottish landlords until the end of the 19th century. “This tainted history explains not only the antipathy towards Scotland, which continued well into the 20th century, but also the persistent nostalgia for a romanticised, Nordic past, which is most apparent in the Viking festivals of Up Helly Aa, held around the isles each winter.” (http://www.newstatesman.com/blogs/malachy-tallack/2007/04/shetland-scotland-independence).
Nor are those islands which have oil fields about them unaware of their potential from bringing considerable wealth to the small island populations . Here is Tallack again: “Throughout the 1970s and 80s, while the Scottish nationalists were shouting from the rooftops about “our oil”, there was a faint but significant murmur from the Northern Isles that, actually, it’s ours. “When the North Sea was first being explored for oil, Shetland was quick to see the possibilities. The Zetland County Council Act was passed by parliament in 1974, giving the local council full control over all developments around the isles, and also allowing them to build up a massive oil fund over the following years. It has made Shetland into one of the wealthiest parts of the UK. The oil terminal at Sullom Voe became the largest in Europe, handling, at its peak, 1.4 million barrels a day, and although production has decreased since that time, the terminal is expected to last until at least 2020.”
There is serious political support in Shetland for more control of their affairs, including the oil, viz:
‘Calls for devolution are nothing new on this remote archipelago which lies more than 60 miles north of John o’ Groats, but the remarks of Sandy Cluness are likely to carry more weight than most. Because Mr Cluness is the convenor of Shetland Council and one of the most influential voices on the islands.
‘Calling for “a more beneficial, more autonomous type of government”, he said that a full of range of services, from transport and policing to coastal protection and the arts, could be administered from Lerwick, the capital. His favoured solution is a Shetland assembly with tax-raising powers.
‘“What these islands need are viable, profitable economies and one way you can create that is through the ability to vary rates of taxes. In the 21st century there must be some way that the government could look at a different status for Shetland,” said Mr Cluness, who has no party affiliation.’ (http://www.timesonline.co.uk/tol/news/uk/scotland/article5120287.ece) .
The likelihood is that the islanders with oil would prefer to remain part of the UK rather than go with an independent Scotland because they would get a better and more secure deal with the UK. An independent Scotland would be seriously strapped for cash both because of the obligations it would have to take on such as a proportionate share of the UK National Debt (https://englandcalling.wordpress.com/2011/06/02/the-wages-of-scottish-independence-public-debt/) and its very heavy dependence on public sector employment (https://englandcalling.wordpress.com/2011/05/19/the-wages-of-scottish-independence-public-sector-employment/). That would make any Scottish government less likely to be generous to places such as Shetland. The loss of great swathes of oilfields to the islands would utterly undermine the SNP belief, gravely flawed as it is, that oil would fund an independent Scotland. (https://englandcalling.wordpress.com/2011/05/14/the-truth-about-uk-oil-and-gas/). But even those islands without oil nearby would probably prefer the security of being part of the UK because they currently get a disproportionately large share of funding from both the UK Treasury money and the EU. That would be at risk if Scotland were independent. There is great potential for friction between the highlands and islands and the lowlands. Scotland gets a much higher per capita payment than England from the UK Treasury at present, around £1,600 per head or an additional £8-9 billion. (https://englandcalling.wordpress.com/2010/11/12/celtic-hands-deep-in-english-taxpayers%E2%80%99-pockets/). This disparity is a consequence of the Barnett Formula (http://www.timesonline.co.uk/tol/news/uk/scotland/article5489186.ece). This was devised in the 1970s, ironically as a short-term measure to provide higher funding for Scotland (Wales and Northern Ireland came in later) on the grounds that Scotland had greater needs due to things such as a worse health record and a scattered population (http://www.parliament.uk/documents/commons/lib/research/rp98/rp98-008.pdf). A disproportionately large amount of the UK Treasury money sent to Scotland is spent on the highlands and islands. An independent Scotland would lose the English subsidy and have to direct more of its own money away from the 4.7 million in the lowlands to the 450,000 in the highlands and islands.
Then there are the many EU grants which go to the highlands and islands, for example, these from 2011: http://www.bbc.co.uk/news/uk-scotland-highlands-islands-12108095. Most of these require matching funding from recipient country. At present the matching funding comes from the UK Treasury. After independence Scotland would have to find the matching funding, something it would find exceedingly difficult to do. There is also the serious possibilities that Scotland might not be admitted to the EU or the EU might be radically changed by the present problems within the Eurozone or even break up altogether. In any case EU funding for Scotland is going to be reduced by 2020 (http://www.eprc.strath.ac.uk/eprc/documents/PDF_files/Scotland%20Europa.pdf ).
Religion is not a problem in England and Wales. It is in Scotland. The broad religious divisions are between Catholic and Protestants , both between the historically Protestant lowlands and the Catholic Highlands and as a consequence of immigration between Ireland and Scotland (both ways) since the 16th century.
The Highland Clearances left only a small population, so the primary cause of friction today is between the Catholics and Protestants of the lowlands. This is most heavily concentrated in the south-west of Scotland with a focal point of Glasgow. These lowland Catholics and Protestants carry on the internecine strife of Northern Ireland, a fact most publicly seen in the often violent support for the two major Glasgow football teams, Celtic (Catholic) and Rangers (Protestant), although Edinburgh has its own version with Hearts (Protestant) and Hibernian (Catholic) (http://www.sconews.co.uk/news/8052/sectarianism-bigger-than-an-old-firm-fixture/). There is Sectarian marching (http://scotlandonsunday.scotsman.com/religiousissuesinscotland/Marching-season-costs-under-fire.5536867.jpis) and a school system in the West of Scotland divided on sectarian lines (http://www.ekklesia.co.uk/node/15012) .
The situation in Ireland both north and south still has very real potential to boil up into serious violence. The “Peace Settlement” in the north has merely been a papering over the cracks. Violence has been low key while a great deal of money and other privileges was pumped into Northern Ireland and the Republic of Ireland (RoI) was living in the fantasy world of the “Celtic Tiger” as the housing bubble swelled and the EU subsidies flowed in. But since the present financial crisis began in 2008, there has been the ruination of the RoI’s economy and the north is faced with reductions in its massive subsidy from England. Already there have been sporadic outbreaks of sectarian violence in Ulster over the past few months (http://www.telegraph.co.uk/wirecopy/8590849/Shots-fired-in-fresh-night-of-violence-in-east-Belfast.html) and there is a fair chance that if the economic situation in Ireland continues to be poor or deteriorate, from what is already a parlous situation in the RoI , “The Troubles” will re-ignite. If that is the situation after Scotland obtained independence it is probable that the nationalist-loyalist feud would be played out in Scotland, not merely through riots at football matches and marches, but with real terrorist violence. Scotland could also become a place where weapons were stashed for the warring factions in Ulster and a refuge to which Irish terrorists retreated when thing s got too hot, just as they used to keep stashes of weapons in the RoI and retreated there for safety before the “Peace Settlement” . Irish terrorists might also use Scotland as a base from which to attack England.
Finally there is the question of ethnic minorities. The proportion of these in Scotland was 2% (100,000 people out of 5 million) at the 2001 Census (http://www.scotland.gov.uk/Publications/2004/02/18876/32939). That is considerably below that of England, but the absolute size of population counts for more than the percentage. A population of 5 million can be quickly overwhelmed by mass migration. Add one million more ethnic minorities to those already in Scotland and they form twenty per cent of the population. Add one million more to a population the size of England (50 million) and it only increases the percentage of ethnic minorities by two per cent. It is not a massive problem at present, but there have been pointers to what would happen if a large influx of foreigners suddenly arrived in the hostile response to asylum seekers housed in Scotland for an example, see http://news.bbc.co.uk/1/hi/scotland/1483315.stm.
It is difficult to see how such a varied society with so many potential points of serious conflict would be able be able to function coherently as an independent state. The population being small would amplify the differences, because the fewer the numbers the easier it is to be heard. Nor is the record of the Scottish Parliament in handling its finances to date been encouraging, with the massive cost over-run for the Parliament building (initial cost projection £50 million; actual cost £414 million http://www.undiscoveredscotland.co.uk/edinburgh/scottishparliament/index.html) and the Edinburgh tram system fiasco which has seen a planned cost of £500 million soar to £750 million with the prospect that the entire cost may be written off and no tram system built (http://thescotsman.scotsman.com/edinburghs-new-tram-network/Leader-Humiliation-looms-over-trams.6789657.jp). If an independent Scotland’s finances are rotten, then the project is likely to turn turtle.