In what was almost certainly the most powerful speech of his career, the prime minister used his speech to the Labour conference to synthesise an uncompromising hostility to Osama bin Laden's terrorist network - and the Taliban if they do not give him up - with a vaunting promise to remake the world as a better place.

The sweep and moral fervour of the 54-minute address caught friend and foe off guard. There were no party political jibes and barely a triumphalist mention of Labour's historic June 7 election victory. The Conservatives damned the performance with faint praise.

Evidently sensitive to charges that he was sounding too confrontational, Mr Blair acknowledged that many people are fearful of what lies ahead - and sought to reassure voters whose unwavering support is vital to a long campaign.

"Our way of life is a great deal stronger and will last a greal deal longer than the actions of fanatics, small in number and now facing a unified world against them. People should have confidence. This is a battle with only one outcome: our victory, not theirs," he insisted.

Admitting his own helplessness in the face of so much bereavement on September 11, Mr Blair had earlier said of the dead: "They don't want revenge, they want something better in memory of their loved ones. I believe their memorial can and should be that out of the shadow of this evil should emerge lasting good."

The speech, which was, unusually, drafted by Mr Blair himself, also reflected his private moral preoccupations to an unusual degree. But before a largely secular audience it was repeatedly punctuated with bursts of applause in the packed but sombre Brighton conference centre, where the foreshortened 2001 conference ends today.

As the prime minister sat down he was praised for his vision and tone by friends and critics alike within Labour's ranks, though delegates may come down to earth with a jolt when they size up to the challenges he posed in the name of "the power of community" - local and global - to do good.

"He didn't deal with the whats and hows, but he certainly explained the why," said one former cabinet member. Some leftwingers and trade unionists, irked by the address's religiosity, called it "messianic" and lacking commitment to the means of righting the world's wrongs.

They were a minority. "Brilliant," said a senior colleague after hearing his party leader - famous for his regard for business tycoons - declare: "The starving, the wretched, the dispossessed, the ignorant, they are our cause too."

Throughout the day's debates senior ministers, including Jack Straw, Geoff Hoon and Clare Short, had stressed the importance of adhering to international law in the search for justice - a point echoed by the veteran Tony Benn in an emotional warning against the "sorrows of war".

An end to famine, poverty and corruption in Africa, as well as genocidal conflicts such as Rwanda's, were only part of an agenda that foresaw the world tackling such intractable problems as global warming and the Israeli-Palestinian conflict - an "equal partnership" side by side in their own lands.

Though the back half of Mr Blair's text addressed the domestic agenda - the need to put improved public services before tax cuts - he repeatedly went out of his way to reconcile Islam with the west, above all with America.

For all its flaws the US, where a black child of poverty such as Colin Powell could rise to be secretary of state ("I wonder frankly whether such a thing could have happened here") was still a model to the world, he argued.

Nor had America lashed out, as some had predicted: "no missiles on the first night just for effect". When military strikes came they would be "proportionate, targeted - we will do all we humanly can to avoid civilian casualties".

While the west must address its shameful ignorance of Islam, he later suggested, "it is time also for parts of Islam to confront prejudice against America" - not only Islam, but "parts of western societies too". That was loudly applauded in a conference where such sentiments have long existed.

But Mr Blair's conciliatory and idealistic tone was not extended to the enemy of the moment, whose version of Islam was "no more obedient to the proper teachings of the Koran" than the crusaders of the Middle Ages had exemplified the gospel message, he said.

"Be in no doubt Bin Laden and his people organised this atrocity," Mr Blair insisted. He offered no evidence, although he did suggest that terrorism finances itself through Afghan heroin sold on the streets of Britain.

His contempt for the Taliban and their denial of human rights, especially for women, was stinging. But he did not say, as Labour briefers had indicated overnight, that it was already too late to avoid military retribution.

"I say to the Taliban: surrender the terrorist or surrender power. It's your choice."

Mr Blair's pledge to defeat the "act of evil" that destroyed the World Trade Centre - "if they could have murdered not 7,000 but 70,000 does anyone doubt they would have done so and rejoiced?" - was only the trailer to a declaration that globalisation made cooperation between nations and cultures imperative.

"This is a moment to seize," he said. "The kaleidoscope has been shaken, the pieces are in flux, soon they will settle again. Before they do let us reorder this world around us and use modern science to provide prosperity for all.

"Science can't make that choice for us, only the moral power of a world acting as a community can."