You have to hand it to George Osborne: he’s great at turning massive setbacks to his advantage. He pledged to get rid of the deficit over one parliament, now he’s boldly saying he’ll do it over two. Be had said he’d sort out the economy over five years (after all, Britain won a world war in six) but now - in a well-delivered and well-received speech - he’s solemnly declaring that we’re 'not nearly finished' and he should be re-elected to finish the job. So to prove it, he had a new plan for 2018-20: a new deficit pledge.
As ever with Osborne, it's political. He calculates that Ed Miliband plans to run permanent deficits, as Gordon Brown did. So he’s made a pledge that he believes he Ed Miliband won't be able to match: that government balances its books. Such pledges govern public finances in Sweden and Australia, allowing both countries to enter the crash with strong public finances.
Osborne had plenty to say about the virtues of balancing the books. Here’s a wee sample of it:-
'Never again should anyone doing my job be so foolish, so deluded, as to believe that they have abolished the age-old cycle of boom and bust. So I can tell you today that when we’ve dealt with Labour’s deficit, we will have a surplus in good times as insurance against difficult times ahead. Provided the recovery is sustained, our goal is to achieve that surplus in the next Parliament. That will bear down on our debts and prepare us for the next rainy day.'