THIS week George Osborne, the chancellor of the exchequer, Danny Alexander, the chief secretary to the Treasury, and Ed Balls, the shadow chancellor, all declared their opposition to a currency union with an independent Scotland. Alex Salmond, the leader of the Scottish National Party, dismissed this three-pronged assault as “bluff, bluster and posturing”. He also hinted plainly that Scotland would refuse to take its share of the national debt if it were prevented from sharing sterling and the Bank of England. Commentators (such as our Bagehot) sensed the ground moving. Something seemed to have happened to the debate over Scottish independence. But what, exactly? Were the unionist parties finally getting their act together and bringing the fight to Mr Salmond? Was Alistair Darling, the leader of the campaign to keep Scotland in the union, giving way to more potent politicians? Was a rather dry debate finally turning exciting? Yes, all that—but something else was afoot, too, with more serious long-term consequences for Britain.

Assume that Scotland votes to stay in the United Kingdom this September, as all the polls suggest it will. Unionism will have triumphed. The Scottish National Party will have failed to deliver the very thing that it exists to deliver; it will be forced to refashion itself as the boring, competent manager of a not very large devolved administration. Mr Salmond’s career may be over. But Britain will have been damaged.

After this week, the people of Scotland will remember that Britain’s three main political parties were all prepared to deny them the use of a currency that most of them very much want to keep. If they were paying attention to what Messrs Alexander, Balls and Osborne were saying, they will also recall that Westminster had in effect ruled out rescuing them if one of their big banks imploded. As for the English, Northern Irish and Welsh, they will remember that Scotland’s leader was prepared to stick them with the entirety of the national debt.

Everything that was said this week needed to be said, and not only because much of it was true. It would be disastrous to go into a referendum with all the politicians being terribly delicate about the consequences of independence: a vote to leave would in fact be followed by savage rows over all sorts of things, and it is essential that everybody understand that in advance. The necessary ding-dong that happened this week is nonetheless embittering and corrosive to relations between Scotland and the rest of Britain. Nationalists may well lose the battle for independence. But nationalists fight long wars, and they feed on mistrust and resentment. This week’s row will nourish them.