Bruce Anderson: The evidence is overwhelming - a lot of Scots are suffering from an inferiority complex.

To start with a confession: I do not understand Scottish Nationalism. With the possible exception of the United States of America, the Union has been the most successful constitutional experiment of all time (the USA needed half a million dead in a Civil War before the 'U' was secured). Of course, Scotland could run itself. So could England. But we do it so much better when standing together. In a threatening world, in which we are beset on all sides by dangers, it seems crazy to throw overboard arrangements and allegiances which have worked so well for so long that they ought to be held sacred.

Equally, the Union has been a political phenomenon, not a cultural one. Scotland and England are still distinct nations, and not just on the sporting field. There has been none of the prod-nosing we have come to expect from Brussels in an attempt to impose uniformity. In the United Kingdom, it is possible to be a proud nation without having to be a separate state. Yet the Union is now in peril. There has been a slow but steady erosion of a Unionist political identity - and according to recent polls, that is at least as true in England as in Scotland. I have always feared  that the terminal threat to the Union would come from England. The Scots would take the lead in belligerence, without ever actually marching over the cliff. But the English might finally pull the trigger.

Consider one ot the most important but least analysed developments in modern English politics. In 1966, the English marched off to the football war against Germany under the Union Flag. At that stage, if you had asked the average football supporter about the Cross of St George, he would not have known what you meant. At some stage over the next few decades, that Cross climbed down from the Church steeple and found a new outlet on white-van man's bonnet. The English decided that they wanted their own emblem. Why? No-one seems to know. But it might have had something to do with the realisation that if England had been playing Saddam's Iraq, the Scots would have been cheering for Iraq.

There is a good Scottish word: "scunnered". With an almost onomatopoeic quality, it is far more expressive than "fed up". It may be that an increasing number of English are becoming scunnered at the Scots' willingness to pour scorn on every aspect of the relationship, except the Barnett formula. At the very least, the latest polls suggest that the Union's roots in English affections are not as deep as they were.

If so, the Scots are to blame. I have lived in England for forty years, and have never found it a disadvantage to be a Scot: not ever, not for a single second. Although plenty of Englishmen work happily in Scotland, I have heard far too many stories of people sitting contentedly in a licensed premises and being told to f*** off, you f***ing white settler (Some of the settlers in question were Scots with a public school accent). Kirsty McRae, daughter of Hamish, the distinguished - and always readable - economic commentator, went to Glasgow University, where her grandfather had been Chancellor. Although her name was hardly a repudiation of her Scottish heritage, she had been to school in England and spoke accordingly. So she was often girned and grizzled at. When Tim Clifford was the Director of the National Gallery of Scotland, there were more girns and grizzles: why had the post not gone to a Scotsman? There have been no English complaints about Neil MacGregor.

There is greatness and grandeur in Scotland and its heritage. We Scots have every reason to take pride in our country. But there is no justification for the widespread resentment of England. So what has created this snarling, snivelling mean-spiritedness? It has been abetted by bad history and worse economics. Many Scots now think that they would have been Covenanters in the Seventeenth Century and Jacobites in the Eighteenth. They also carry on as if William Wallace had been a poll-tax protestor who was cruelly put to death by Margaret Thatcher, which brings us to the grievance of grievances. Maggie has been blamed for anything and everything that arouses Scottish discontent. Henry McLeish, sometime Labour First Minister in Holyrood, once alleged that she was responsible for the poor quality of Scottish football.

There is a problem. When Lady Thatcher was born, around ninety percent of Scots lived within fifty miles of a coal mine, a shipyard or a steel works. That ceased to be the case, not because of her malevolence, but because of economic inevitability. Yet millions of Scots evade reality and blame her. Moreover, they would never give her credit for Silicon Glen - the Scottish softwear industry - or for the growth of the financial sector. Needless to say, she is now held responsible for the latter's misfortunes. Just before the crisis, Alex Salmond was boasting about the strength of Scottish banking. He predicted that Scotland would be part of an arc of prosperity, from Ireland to Iceland: excluding England, of course. He appears to have been forgiven for that absurdity. They will never forgive Margaret Thatcher.

The decline of heavy industry was accompanied by the decline of the British Empire. Most Scots were enthusiastic imperialists: not something which appears in the Nats' version of history. Many did very well out of the Empire, which they helped to run. In its prime, the Empire was a source of national pride, in Scotland as much as England. Oddly enough, the English have found it easier to get over the loss.

But none of that explains the grievance mentality which is so deplorably widespread in Scotland. For that, I am afraid, we have to turn to the psychiatrists. The evidence is overwhelming: a lot of Scots are suffering from an inferiority complex. They should be ashamed of themselves.
It might not be wise to make that the main plank in the pro-Union platform. But the quicker that platform is constructed out of sound timber, the better. The PM was right to scorn Mr Salmond's teasings and procrastinations, and to insist on an early referendum with a yes/no question. He should continue in the same self-confident mode. In yesterday's Sunday Telegraph, Iain Martin seemed to be arguing that David Cameron should keep away from the campaign. Nonsense: when the UK is under attack, the Prime Minister of the United Kingdom has a duty to be in the front line. Moreover, a party leader who might seem to have so much to gain from Scottish independence is in an ideal position to insist on the transendent importance of saving the Union. That said, the campaign must not rest on party loyalties. It must mobilise pro-Unionist forces from all parties and none.

It will be a campaign for Scotland, for the Union, for history and for heritage. It will also be a campaign for a quality on which most Scots pride themselves. So let them justify that pride, in a triumphant campaign for commonsense.