Why did Alex Salmond choose this year to hold the Scottish independence referendum? People have said it is because 2014 is the 700th anniversary of Bannockburn, Scotland’s greatest victory over the English, inspiration for that ridiculous last scene in Braveheart. Others believe it is because in July Glasgow will host the Commonwealth Games, after which the Scottish nationalists reckon they will be surfing a wave of yes-we-can enthusiasm.

But maybe Salmond, canny fellow that he is, had another event in mind: next month’s Fifa World Cup in Brazil. Scotland won’t be going to Rio, of course: they are useless at football at the moment. But England will be there, and if ever there were an occasion more certain to elicit anti-English sentiment among the Scots, it is an international tournament featuring the Three Lions. Just think of all that lager hooliganism, synthetic passion and tabloid chauvinism. Many Englishmen hate themselves after a few days of Team Eng-er-land hysteria. The Scots, with their particular sensitivity to Anglo arrogance, are certain to be bursting with disgust. And if by some fluke we were to succeed in carrying off the trophy, the Union would surely be sunk.

The English would be intolerably smug throughout the summer, especially towards its northern neighbours. Sport revolves around bragging to those closest to you, and in no time the Scots would be in a resentful lather. By the time of the referendum on 18 September, after two months of ‘Football’s come home’ celebrations, the Scots would be desperate to separate.

Both nations care about football much more than politics or economics. The fury Scots feel at George Osborne threatening to deprive then of the pound would be as nothing compared to that inspired by the sight of Wayne Rooney holding aloft the World Cup amid a sea of St George’s crosses.

Scotsmen take pride in the fact that their football fans are better behaved than the despicable English. It is an indication of their superiority, they feel. The tartan army is often hailed as a model for travelling sports fans. They don’t take it too seriously. They drink cheerfully and wear silly costumes. Where England fans sing about not surrendering to the IRA, the jocks send themselves up, chanting about their love of Irn-Bru. Good for them. But such generosity does not extend to wishing the English well. On the contrary, there is a tradition in Scotland of vigorously supporting whichever team happens to be playing England. Scottish sports shops can guarantee a bumper summer if they stock up on the team shirts of whoever England is up against.

The Scots like to laugh this sort of sporting antipathy off as a bit of joke, and so it is — but some jokes are deadly earnest. We Englishmen are also fond of saying that for all the ‘auld enemy’ ribbing, there’s an underlying affection between the Scots and the English. But is there really? In international relations, apparently amicable rivalry can turn nasty in a snap.

English fans can be guaranteed to make things worse by being obnoxious both in victory and defeat. In sport our national insecurities are reflected and magnified: narrow losses are treated as historic disasters, minor wins as supreme triumphs. In the Olympics, when we compete as Team GB, our epic self-importance is disguised — though not moderated — by a sort of Sue Barker-filtered bourgeois decency. We can share the ups and downs with the Scots. When England play, however, we are singularly unbearable. (It’s not just football: our rugby fans are arguably even more conceited, though they are at least less violent.)

The good news for Unionists is that England are unlikely to do well. Whitehall mandarins recently calculated that the government probably won’t have to license pubs to stay open late throughout June, because the odds suggested we wouldn’t progress much past the group stage. Nevertheless, it would only take a couple of big wins and a few days of English gloating to imperil the future of Great Britain. Salmond must be rubbing his hands and, for the first time in his life, praying for the England team to pull off a miracle.