Rupert Cornwell: Old allies march in step to a new kind of warfare

A month ago it would have been unimaginable: the President of the United States, sombrely suited, addressing Americans from the venerable Treaty Room of the White House and telling them that he had just launched a war.

Yesterday, on a cool and crisp autumn Sunday, George Bush did just that. In some ways the speech was a reprise of his address to Congress nine days earlier, warning of a long and difficult campaign.

The mission, said Mr Bush, was "just," and America would not waver. "The battle has been joined on many fronts. We will not tire and we will not fail. The United States did not ask for this conflict but we will win it." Even more starkly, he reiterated his challenge to the countries of the world: "Every nation has the choice, either you are with us or against us ... there is no middle ground. If any government sponsors the outlaws and killers of innocents, they become outlaws and murderers themselves. And they will take the lonely path, at their own peril."

The President made clear that this would be a long war, and a war like few others in the past, a war in which air strikes and other military operations would be interspersed with food drops and humanitarian relief to long-suffering civilian populations. The US might be seeking Osama bin Laden, his terrorist camps and networks and now, explicitly, the Taliban regime which sheltered them, Mr Bush said, "but the US is a friend to the Afghan people and to almost a billion worldwide who practice the Islamic faith."

The actions for that reason were "carefully targeted," designed "to disrupt the use of Afghanistan as a terrorist base of operations and to attack the military capability of the Taliban regime".

Events yesterday moved with stunning rapidity after the return of Donald Rumsfeld, the US Defence Secretary, from the Middle East on Saturday. That day, Mr Bush warned in his weekly radio address that for the Taliban, "time is running out" – and barely 24 hours later it did.

The first clue was the early return of the President from his weekend retreat at Camp David. Then, equally unusually for a Sunday morning, Mr Rumsfeld and other top defence officials assembled at the Pentagon, amid news that another senior official had cut short a visit to the Gulf.

Then, at 12.40pm, soon after the first reports of flashes over the Kabul skyline, Ari Fleischer, Mr Bush's spokesman, appeared in the White House briefing room to tersely announce that "another front" in the war against terrorism had begun, and that in 10 minutes, the President would address the nation.

"More than two weeks ago I gave Taliban leaders a series of clear and specific demands ... but none of these demands were met. And now [they] will pay a price," Mr Bush said.

The war against terrorism may be a conflict like no other in recent history with, as Mr Rumsfeld put it, "no D-Day and no surrender ceremony on the USS Missouri [which sealed victory over Japan in the Second World War]." But it has one feature in common with most of the others: the US and its chief ally and alter ego, Britain, leading the campaign on behalf of the "forces of freedom".

"We were with you at the first – we will stay with you to the last," Tony Blair has told America. Last night, that assertion came true. Britain is in military lock step with America, as the Bush administration goes to war.

At moments like these, the so-called "special relationship", which some claim no longer exists, starts to look like a pillar of the world order, an alliance between the country which controlled the largest empire in history, and the superpower which, after 1945, assumed Britain's global mantle.

The relationship's first hour was unquestionably its finest: the tandem of Franklin Roosevelt and Winston Churchill – himself half-American – during the Second World War.

But it has had its later bright flowerings: the empathy between Margaret Thatcher and Ronald Reagan, twin warriors against the Soviet Union, who both lent their names to "-isms" embodying remarkably similar political creeds.

Then came the Gulf war, and Mrs Thatcher's and John Major's instant alignment with George Bush Senior and subsequent enthusiastic military support. "Don't go wobbly, George," was Thatcher's exhortation to the US President then. One can imagine similar private words now as Mr Blair makes the rhetorical running against bin Laden and the Taliban.