Leading article: The cracks behind this facade of unity

On the face of it, Labour's five days in Manchester will go down in the annals as a successful conference. The delegates dispersed yesterday in better heart than when they assembled. The Chancellor delivered a decent speech that did nothing to damage his prospects of succeeding Tony Blair. The Prime Minister gave a scintillating performance, setting in train his long goodbye while still at the top of his game. And John Prescott's "Sorry" at the start of his closing address was capped only by his footnote that this would be his last conference in his present capacity, too.

The only discordant note was Cherie Blair's overheard comment about the Chancellor. But this was so deftly defused by her husband the next day that it was almost possible to believe the whole episode was just part of the rich texture of Downing Street family life. When the curtain came down, it was on the sort of operatic finale in which all conflicts are resolved, all singles are paired, and everyone departs to live happily ever after.

Except that the conflicts have not been resolved. And while they remained hidden at Manchester, behind expert stage-management and the desire of the party's leading lights not to mention the delicate matter of the succession, they lay only just beneath the surface. The muffled furore about Mrs Blair's alleged remark showed just how easily the facade of unity would crack.

The ever-lengthening queue of contenders for the deputy leadership - a vacancy not even advertised until yesterday - cannot disguise the reality that the jockeying for the top job has already begun. Mr Brown threw down the gauntlet with a speech that staked his claim to be the heir. It was possible to detect hints of ambition in Alan Johnson's contribution, in the measured contribution of David Miliband, and in the powerful speech of John Reid yesterday. He strayed from his Home Secretary's beat just enough to suggest a hankering after a wider brief. As yet, there is no one who runs Mr Brown even close - but this is not the same as saying that poisonous faction-fighting will be avoided.

An exceptionally difficult nine months or so awaits. Mr Blair clearly intends to run the country until the day he announces the date of his departure. Mr Brown will be both Chancellor and contender for the duration, facing all the risks that attend such a dual role. He is constrained from fully setting out his political vision, both for how he would run the country and how he would attack the Opposition. All the while, David Cameron has further opportunity to define both himself and his likely rival. And any setbacks for Mr Brown will open opportunities for a rival that are not apparent now.

This conference has perpetuated other illusions. The approval that greeted Mr Blair's announcement that he would devote his remaining time as leader to diplomacy in the Middle East ignored the awkward truth set out by the UN Deputy Secretary General, Mark Malloch Brown, in his interview today. Mr Blair, he said, had been in many respects, "the best international leader of his time", but there was the tragic error of Iraq "on the other side of the ledger". Does Mr Blair still not comprehend how thoroughly his international standing has been discredited?

Last, but not least, is the threat to Labour from the Conservatives. Mr Blair's forensic jibes at Mr Cameron helped to instil an air of confidence in the party that verges on complacency. Yet several of Mr Blair's attacks - on foreign policy, crime and nuclear power - came from the right. Is this really the position from which Labour wants to fight the next election? The danger is that in a time of political flux, Labour spends too much time and energy fixing its internal difficulties rather than developing a coherent strategy for the future.