Mr Tony Blair braced Britain for military engagement last night, directly targeting Osama bin Laden. He warned Afghanistan's Taliban regime to "surrender the terrorists or surrender power".
He also pledged to back America "to the last" in retaliation against those responsible for "an act of evil" in Washington and New York on September 11th.
At the same time Mr Blair electrified the Labour Party conference in Brighton with a vision of a new world order, rooted in a sense of global community, combining "a fight for freedom" with "a fight for justice too".
In doing so, the British prime minister carved out a British world view - from the problems of Africa to the crisis in the Middle East and the need to implement the Kyoto agreement on climate change - dramatically different from anything previously associated with President Bush.
And he offered this answer to the current crisis: "Not isolationism but the world coming together with America as a community."
Acknowledging the fears of British citizens about this "new situation", Mr Blair warned: "Whatever the dangers of the action we take, the dangers of inaction are far, far greater."
There was "no diplomacy" to be had with bin Laden or the Taliban regime, he declared: "Just a choice: defeat it or be defeated by it."
But people, he said, should be confident: "This is a battle with only one outcome; our victory not theirs."
Moreover, Mr Blair hailed the unfolding international crisis as "an extraordinary moment for progressive politics", speaking of freedom beyond "the narrow sense of personal liberty" but "in the broader sense of each individual having the economic and social freedom to develop to the full". That, he declared, was what "community" meant: "Founded on the equal worth of all. The starving, the wretched, the dispossessed, the ignorant, those living in want and squalor from the deserts of northern Africa to the slums of Gaza, to the mountain ranges of Afghanistan: they too are our cause."
In a bravura performance appealing to the left and right of his party, Mr Blair charged: "This is a moment to seize. The kaleidoscope has been shaken. The pieces are in flux. Soon they will settle again. Before they do, let us re-order this world around us."
Humankind today had all the technology either to destroy itself or provide prosperity to all, said Mr Blair: "Yet science can't make that choice for us. Only the moral power of a world acting as a community can."
He continued: "By the strength of our common endeavour we achieve more together than we can alone.
"For those people who lost their lives on September 11th and those that mourn them, now is the time for the strength to build that community. Let that be their memorial."
Mr Blair said the events of September 11th had brought governments and people around the world to reflect, consider and change.
In this process, he said, "amidst all the talk of war and action" there was another dimension appearing. "There is a coming together. The power of community is asserting itself. We are realising how fragile are our frontiers in the face of the world's new challenges."
To those who suggested Britain was only acting because the US had been attacked, Mr Blair recalled opposition to the action against Mr Milosevic in Yugoslavia. If Rwanda happened again as in 1993 they would have "a moral duty to act there also".
Britain and America could not do it all, he said, "but the power of the international community could, together, if it chose".
Citing the continuing conflict in the Congo, Mr Blair spoke of the possibility of "a partnership" for Africa.
"We could defeat climate change if we chose to," he went on: "Kyoto is right. We will implement it and call upon all other nations to do so."
If humankind was finally able to make industrial progress without the factory conditions of the 19th century, said Mr Blair, "surely we have the wit and will to develop economically without despoiling the very environment we depend on".
And, he ventured: "If we wanted to, we could breathe new life into the Middle East peace process, and we must."
In one of the most warmly applauded sections of his speech, Mr Blair told the conference:
"The state of Israel must be given recognition by all; freed from terror; know that it is accepted as part of the future of the Middle East, not its very existence under threat.
"The Palestinians must have justice, the chance to prosper and in their own land, as equal partners with Israel in that future."
Declaring it time for the West to "confront its ignorance of Islam", Mr Blair praised the US as "a free country, a democracy our ally" and said some reaction to the attacks on New York and Washington had betrayed "a hatred of America that shames those that feel it".