Tony Blair's speech to Congress may have been a powerful restatement of his personal belief that he did the right thing by going to war on Iraq.
But it also contained another subtle but significant shift of tack in the justification for the war.
Blair's strong words received standing ovations from Congress
He declared that, even if no link between weapons of mass destruction and terrorism was proved, it was still right to have removed a brutal and murderous dictator from power.
Just as significantly, in a wide ranging speech which brought numerous standing ovations, he did not repeat his previous confidence that he would find weapons of mass destruction in Iraq.
He did not even use his new formula, that weapons "programmes" and "products" of those programmes would be found.
And his comments came only days after a senior Whitehall source, claimed by some to have been Foreign Secretary Jack Straw, told the BBC weapons of mass destruction may never be found.
So, as the Washington speech again demonstrated, Mr Blair is preparing the ground for a fresh justification for war in the event WMD never turn up.
In that event he will state that removing Saddam Hussein was justification enough.
This is all a million miles away in tone from the pre-war hype.
At that time, the prime minister regularly warned of the inevitability of WMD finding their way into terrorists' hands.
But his overwhelming justification for war was the immediacy of the threat from Saddam Hussein.
Indeed, it was pretty clear at the time that regime change was not only not a reason for war, but that it may even have been illegal.
And, while many of his own MPs and the public may have agreed Saddam should have been removed, it is far from certain they would have backed war on that basis.
And it is still certain that, if he does not turn up those weapons, his leadership will be in crisis.
In the meantime, Mr Blair will hope his powerful speech in which he urged the US to accept its destiny, work with others and listen more, will pay dividends at home.
He lavished praise on the US for its principles of liberty and freedom but he went on to insist it must act on crucial global issues including a Middle East peace, protecting the environment and resisting any moves towards isolationism.
It was clearly intended to be a keynote speech which would help redefine the relationship between Britain, the US and Europe.
He clearly wanted to move beyond the detail of the recent troubles buffeting both his leadership and the presidency and look forward to historic challenges and opportunities.
Whether it helps bolster his position at home remains to be seen.
What remains certain is that, if he fails to win the peace in Iraq, the rest of his vision will quickly evaporate.