THE most extraordinary thing about next year's independence referendum is that it is happening at all.

We could be only 15 months away from the dissolution of one of the most successful political unions in history: the United Kingdom, a country whose empire once dominated the planet. Yet Scotland has no real history or tradition of political nationalism, at least not on the scale of Ireland or any of the former British colonies that sought independence in the 1950s and 1960s.

And there's a very good reason for this. Scots have not rebelled against the UK because, for most of the last 300 years, Scots have been among its most enthusiastic supporters. They helped create it, after all, after 1707 along with the currency union based on sterling. The Bank of England was even founded by a Scot, William Paterson. Which makes it offensive to hear unionists like Chancellor George Osborne threaten to deny Scotland the use of its own currency. It's like denying the pound and the Bank of England to Yorkshire.

When Scotland gave up its parliament in 1707, it wasn't quite the corrupt annexation that has been presented in Jacobite lore, or in the ambiguous poetry of Robert Burns. Nor was it the last gasp of a nation impoverished by the Darien disaster, which is how it tends to be presented in some school history books. The Treaty of Union was essentially about security: about ending 300 years of debilitating warfare between Scotland and England that had continued, and even intensified, after the Union of the Crowns in 1603, which was supposed to have ended this historic enmity.

King Edward's armies may never have conquered Scotland and extinguished Scottish nationhood, but Oliver Cromwell's roundheads nearly did after 1650. The Wars of the Three Kingdoms, and the turbulent Stuart Restoration that followed, left Scotland exhausted physically, economically and spiritually. It has been estimated that 100,000 Scots died in these terrible conflicts, in a population of little more than one million.

Economic and political union was seen by its advocates as a way of resolving this conflict by creating a new economic and political entity, Great Britain – rather as the European Union was seen as a way of ending conflict between France and Germany. And it worked – even though, crucially, Scotland and England remained nations with their identities intact. The abortive 1745 Jacobite rebellion was the last battle ever fought on British soil.

England didn't move for the treaty out of altruism, of course. It wanted the security of the Hanoverian succession, and it also needed Scottish taxes and Scottish men to fight its battles with France. Scotland's parliament was folded into Westminster with indecent haste. However, losing a parliament was not considered as great a loss in 1707 as it would be today. Scotland was not a democracy at the start of the 18th century, it was more like a theocracy, dominated by the Presbyterian Kirk.

The old Scottish parliament before 1707 was more like a chamber of commerce for the nobles, lairds and burgesses – people of property. Yes, "a parcel o' rogues" were shamelessly bribed by Queen Anne's agents into voting for the Treaty of Union. And yes, many Scots did riot against the 1707 Union, especially when they discovered that they were expected to pay for it through an array of new taxes, like the hated Malt Tax on alcoholic beverages. But, crucially, the Presbyterian Kirk accepted the deal because the Acts of Union left it in sole charge of its own religious turf, and for most Scots this was more important than the location of a parliament in which they had no say.

Scottish merchants and money-lenders got what they wanted: access to the lucrative markets created by the British Empire. By the 1750s, they had started to make good money out of tobacco, the slave plantations of Jamaica and the cotton trade, which helped fuel Scotland's mills in the early industrial revolution. Meanwhile, many lower-class Scots, some of whom had fought for Bonnie Prince Charlie against Cumberland's redcoats in the '45, were enlisted into the British army and became the shock troops of the empire.

From Quebec to Balaclava, from the Indian Mutiny to the First World War, it was generally the Scots who went over the top first, suffering the worst casualties. Their exploits were glorified in epic Victorian paintings like The Thin Red Line and Scotland Forever. These were the blockbuster films of their day and lent a mystique and celebrity to the Scottish soldier which still exists to this day in plays like Black Watch.

Scots saw themselves as partners in the empire albeit junior ones. The Scots fought Britain's wars, kept its books, ran its colonial administrations, evangelised the heathens. By the mid-19th century, Scots were flattering themselves that they were the best bit of the empire; the hardy ones who did the work, handled the natives and even lent a moral dimension through the efforts of Scots missionaries like David Livingstone.

Back home, the fantasy image of the heroic Highlander, created by the novels of Sir Walter Scott, captivated Victorian England and helped turn Scotland into a deer-hunting theme park for the English upper classes. They were often clad in tartans invented by the Highland Society of London, and wearing the short kilt or philabeg, which was popularised, if not created, by an Englishman, Thomas Rawlinson, and bore little relation to the great plaid worn by true Highlanders.

Scots rather liked being regarded by the English as fearless warriors, canny entrepreneurs and prudent bankers. Being a patriotic Scot, and celebrating Wallace and Bruce, became a way of expressing Britishness in Scotland. The mighty Wallace Monument outside Stirling was built in the 1860s. Scotland became a hub of the British Industrial Revolution, thanks to James Watt and his steam engine. By the end of the 19th century, Scotland was arguably the most technologically advanced country in the world after England, and Glasgow called itself the Second City of the British Empire.

Working-class Scots didn't get much change from it, however. Edinburgh's slums in the 19th century were almost as bad as Calcutta's. Scots, many cleared off their ancestral lands by former clan chiefs, were turned into industrial wage slaves. But their patriotism, and their Presbyterian religion, consoled many Lowlanders, and seemed to immunise Scotland from the political nationalism that swept Ireland and Europe in the 19th century. And while 1848 may have been springtime for nations on the Continent, it was still winter in Scotland. Scots continued to respond to the call of the British empire in 1914, enlisting in prodigious numbers and dying disproportionately in the trenches.

The Second World War is often called the "high noon" of the Union, as Scottish and English fought together to defeat fascism. And they fought side by side again afterwards to create the welfare state, a new post-imperial social contract, defined by the NHS, sponsored by the 1945 Labour government. It really did look like a land fit for heroes in the 1950s, as the slums were cleared, Scottish wages tripled and infant mortality became a thing of the past. Scots probably never felt more British than they did in the early 1960s, as popular culture and television made the Border seem irrelevant.

Scottish nationalism was certainly irrelevant in post-war Scotland. The SNP, created in 1934, barely registered in elections until 1967 when Winnie Ewing won the safe Labour seat of Hamilton. That, plus the discovery of Scottishoil, launched the wave of constitutional innovation that ultimately led to the creation of the Scottish Parliament in 1999. However, it was Margaret Thatcher, and her poll tax, who finally convinced Scots that they needed to restore their parliament, essentially as a defence against Tory governments in Westminster.

But this was very much Labour's Scottish Parliament – the SNP having boycotted the cross-party Scottish Constitutional Convention that devised it. Holyrood was delivered on the back of the 1997 UK Labour landslide as a subordinate, devolved parliament within the UK. But the future First Minister, Donald Dewar, delivered the Scotland Act that handed genuine sovereignty to the Scottish Parliament. In the early years of devolution, it looked as if the Scottish Parliament really had "killed nationalism stone dead" as the former Labour shadow Scottish secretary, George Robertson, had forecast in 1996. As late as 2003, the SNP's support was in steep decline in the Scottish parliamentary elections.

It was only the return of the "absentee landlord" Alex Salmond, from voluntary exile in Westminster, that allowed the SNP to crawl to power in 2007 over the ruins of the Scottish Labour Party, whose period in office had been marked by scandals and resignations. Scots were so relieved at the SNP's performance that they re-elected Salmond with a landslide in 2011, making the referendum inevitable. The Scottish Parliament had thus been the incubator for the first time of a genuine political nationalism in Scotland.

However, it is important to stress that most Scots were not voting for independence in 2011, but for a better devolution. Scottish voters have told opinion pollsters repeatedly over the last 30 years that they do not want to leave the UK, but want a stronger, essentially federal parliament with a full range of economic powers, while leaving policy on defence and foreign affairs with Westminster.

The most recent confirmation came in the Scottish Social Attitudes Survey in January of this year. In this most exhaustive independent survey of Scottish opinion, two-thirds said either that the Scottish Parliament should take all decisions for Scotland (35%) or that it should make all decisions apart from defence and foreign affairs (32%). Yet this is the one option that Scots are not allowed to choose in next year's referendum.

It isn't hard to see why so many Scots are confused and irritated about the referendum in September 2014. They will be faced with a choice of unacceptable alternatives – independence or the status quo – in a referendum they never really asked for. Moreover, Alex Salmond, in trying to tailor his message to mainstream Scottish opinion, has confused matters by talking of a new "social union" in which Scotland would keep the Queen, the pound, Nato bases, UK pensions and so on.

So, on the one hand, we have the SNP offering a form of ersatz autonomy, which leaves so much power with Westminster it is hard to call it independence. On the other, we have the reactionary unionism of Labour MPs in Westminster, who won't even allow their own Scottish leader, Johann Lamont, to contemplate more powers for Holyrood, as was demonstrated by their rubbishing of her tentative tax proposals in March.

Scots are increasingly confident that Scotland could become a viable independent country if they really wanted. The great change in the Holyrood years has been the increasing acceptance by both sides of the independence debate that Scotland, with its burgeoning oil industry, its financial services, its universities, renewable energy resources and so on, has the means to become an independent state just like Denmark of Norway. Scotland increasingly resembles a Nordic country in terms of economic and political culture. This is apparent in the continuing commitment in Scotland to collective provision expressed in policies involving elderly care and student fees, and opposition to the commercialisation of the NHS.

However, it is understandable that the Scots should not want to discard the UK because they helped build it, even if it is looking unfit for purpose. With a Conservative-led government back in Westminster, the divergence of political culture between Scotland and England is becoming more pronounced. "Tory" is still a four-letter word in Scotland. Scots can no longer be confident even of remaining in the European Union now that the UK Conservatives are committed to an in/out referendum.

The worst that could happen in 2014 is an inconclusive and bad-tempered referendum campaign after which a No vote is taken by Westminster as a sign that the Scottish question is no longer important. This is what happened after the 1979 referendum, which failed to meet the 40% rule. UK governments then allowed Scotland's manufacturing economy to be dismantled, while the UK balance of payments deficit was being financed by Scottish oil revenue.

To avoid that fate, many Scots may be tempted to vote Yes in September 2014, even though they don't want independence. Others may vote No, even though they want a deeper form of devolution. The fate of Scotland may be decided by the frustrated middle who decline to make any choice at all. It would be the ultimate irony if Scotland left the UK through apathy.

Road To Referendum – a three-part series examining the history and development of the independence question in Scotland – begins on STV on Tuesday at 8pm, and continues on June 11 and 18.

A companion book, Road To Referendum, by Iain Macwhirter, is published next week by Cargo Publishing, £13.99. It will be launched at an Aye Write! event featuring Iain Macwhirter and broadcaster Kirsty Wark, at the Mitchell Library, Glasgow, on Monday, June 17, 6.30pm, For tickets (£6) visit www.ayewrite.com, call 0141 353 8000, or visit the Glasgow Royal Concert Hall in person.