Having won the historic Commons vote Prime Minister Tony Blair must now carry the country with him as he looks to war and the post-Saddam reconstruction of Iraq.
Any time now, probably as the first bombs fall on Baghdad, Mr Blair is expected to address the British people directly, echoing Downing Street's call yesterday for parliament and public to rally behind the British forces in the Gulf.
The initial signs are promising. In his famous resignation speech on Monday night Mr Robin Cook disavowed a war entered upon without widespread international or domestic support. However Number 10 always anticipated that that situation would change as conflict drew near. Yesterday's YouGov poll for The Daily Telegraph provided the first substantial evidence that British public opinion is moving behind Mr Blair.
While more than half those surveyed said they were unimpressed with the diplomatic skills of Mr Blair and President Bush, 50 per cent said Britain and America were right to take military action as opposed to 42 per cent who thought them wrong.
Significantly, in terms of the ongoing blame-game over the failure of UN diplomacy, 68 per cent said President Chirac was wrong to say France would veto any UN resolution triggering the use of force if Saddam failed to disarm. Just 2 per cent blamed Mr Blair most for the failure of the Security Council to work together to deal with the Iraq crisis, as opposed to 35 per cent who blamed President Bush and 50 per cent who blamed President Chirac.
And crucially perhaps, as an indicator of the trend in public thinking Downing Street is banking on, 53 per cent said they had a great or fair amount of trust in Mr Blair to take the right decisions from now on about military action.
Mr Blair has emerged from a gruelling week with other credits.
A widespread verdict yesterday was that he had not only won the Commons vote but also the argument. There seemed something pitiful about Clare Short's argument that "here is where we are" and that it would have "cheap" of her to follow-through her resignation threat "as though he [Tony\] could do something different now."
This in fact is the perfectly respectable position many Labour MPs will already have arrived at, even after following their conscience and voting against Mr Blair in Tuesday's second record Labour revolt.
Unfortunately Ms Short - a caring person, who has been a good International Development Secretary - raised herself ahead of the final diplomatic endgame in a manner which appeared to elevate her qualms of conscience over those being experienced by the rest of her cabinet colleagues. She volunteered herself for that famous interview on the BBC's Westminster Hour in which she categorically said she would resign if there was not UN authority for war and, also, UN authority for the reconstruction of Iraq thereafter.
"She loves to fight with her conscience and she always wins," was typical of the disdain which greeted her spectacular announcement that she would remain in cabinet after all.
Had she only held her tongue Ms Short could thus have wholly justified her continuation in a cabinet led by a prime minister who had won a mandate for war from the governing Labour Party and from parliament as a whole, having been left no alternative by the threatened exercise of the French veto in all circumstances.
Instead those colleagues who had counted on her resignation alongside Robin Cook to embolden Labour dissidents were left in dismay, questioning the judgments which inclined Ms Short to oppose war without UN approval while persuading her she was peculiarly necessary to the reconstruction which must follow.
The prickly Mr Cook is not seen as a likely successor to Mr Blair. However Labour insiders say he and Ms Short together could have formed a powerful focal point for wider Labour discontents in the post-war situation, and could have anticipated a return to office should Gordon Brown eventually realise his ambition to take-over from Mr Blair.
As it is, Downing Street - though they would never publicly admit it - will regard Ms Short now as an entirely disposable commodity, no longer the "licensed conscience" of the cabinet or of the wider parliamentary Labour party.
The disbelief at Westminster on Tuesday was focused on an apparent failure of political instinct and intelligence which should have told her as much. But she surely finally "got it" if she caught the television images of Mr Blair smiling as the former Conservative leader William Hague described the prime minister's decision to keep her in the cabinet as his "revenge" for her charge of recklessness.
That Mr Blair resisted the knee-jerk instinct to sack Ms Short says much about his strength and political skill. Beyond considerations of mere party management, however, a greater measure of the man is that - against virtually all expectations - he broke with precedent and allowed MPs to have their vote before the decision to commit British forces to action.
The final decision will still be exercised under the Royal Prerogative.
However Mr Blair has changed the rules for future engagement. At the start of this momentous week, few would have imagined that the House of Commons, as well as Mr Balir, would emerge a victor.