Don't say they didn't warn us. Even as debate is raging on both sides of the Atlantic over the threat of war against Iraq, US leaders have already declared their hand. George Bush's defense secretary, Donald Rumsfeld, this week announced that the US could not afford to wait for "additional" evidence about Saddam Hussein's weapons program before taking action. That followed national security adviser Condoleezza Rice's insistence that "we certainly do not have the luxury of doing nothing" about the "powerful moral case" for regime change. And earlier this month Bush himself boasted he would use all the tools at his disposal to topple this "threat to civilization", who was "thumbing his nose at the world". All three were in conclave in Texas yesterday, as US military preparations mount in the Gulf, bombing raids by British and US warplanes on southern Iraq intensify - there were three in the past week, out of 28 so far this year - and war fever pushed oil prices over $30 a barrel.

With the failure to capture Osama bin Laden or Mullah Omar, the overthrow of Saddam has become the war on terror. And the US administration shows every sign of pressing ahead in splendid isolation. Internationally, only Israel appears to be committed to an attack, even if Tony Blair's loyalty is taken for granted in the White House. But in the US itself, what is striking is the narrowness of support for war on Iraq at the heart of the political establishment. When Republican hard men such as Henry Kissinger, Brent Scowcroft and the victor of the 1991 Gulf war, Stormin' Norman Schwarzkopf, come out against Bush Jr's return match, the president might be thought to be in some difficulty. Presumably the assumption is that, with polls recording strong support among the US public, dissent will be duly stilled when the call comes.

No such comfort is available in Britain, where opposition to a new assault on Iraq has reached critical levels. Put on one side the legions of bishops, retired generals, mandarins, Tory grandees, ex-ministers and trade unionists lining up to denounce the prospect of war. Even someone like the former Foreign Office minister Lord Chalfont, battle-hardened cold war warrior and a hawk in every conflict for well on half a century, has balked at this one. With the Tory hierarchy refusing to speak out, it has become increasingly hard to find any mainstream figure prepared to put the case for the American adventure. What supporters there are have floundered for lack of a coherent and consistent argument. It hasn't helped that the usual guidance from Washington has been so flaky and would-be cheerleaders have been left begging Bush and Blair to make a proper case for their war.

First the pretext was Iraq's non-existent links with al-Qaida and September 11. Then it was the anthrax attacks in the US, which turned out to be a domestic problem. Then it was the long-running dispute over Iraq's drastically depleted chemical and biological weapons capacity and its resistance to the return of UN weapons inspectors. But now that Saddam has begun to signal a climb down on inspectors (apparently going a good deal further in private messages passed to the US administration via Jordan's King Abdullah), they seem to be something of a side issue after all. As John Bolton, the US undersecretary for arms control, blurted out, the "regime change" policy "will not be altered, whether inspectors go in or not". And according to General Wesley Clark, Nato's commander during the Kosovo war, the Bush administration's hawks concede in private that Iraq is no threat to the US. Meanwhile, it is increasingly widely acknowledged that the only circumstances in which Saddam is now likely to pose a threat to his neighbors is, ironically, if he faces a full-scale American invasion. The implication of all this could not be clearer. The US is committed to overthrowing the Iraqi regime, not because of terrorism or weapons of mass destruction or brutal internal repression, but because it is an obstacle to the imposition of a new pax Americana on the world's main oil-producing region.

The last-ditch argument by the war party is that a US attack, expected to produce further large-scale destruction and civilian casualties, would at least give the Iraqi people what they want. No doubt many Iraqis passionately hope for an end to the rule of Saddam Hussein. But testing Iraqi opinion on the prospect of a new war, or anything else for that matter, is impossible in current circumstances. What we do know is that the Iraqi opposition itself has become increasingly polarized over the expected US assault. Both main influential Islamist parties are opposed to a US attack, as are the communists - the largest political force in Iraq before Britain and the US helped Saddam's Ba'ath party to power in the 1960s. The fact that even those who are directly funded by the CIA and Pentagon - the Iraqi National Congress and Iraqi National Accord - feel obliged to adopt various euphemisms and circumlocutions when expressing support for their paymasters' plans, suggests that a foreign invasion may not be as popular on the ground as some like to imagine. Given the horrific human toll exacted by more than a decade of sanctions and bombing, that should hardly come as a surprise.

Each war fought by the US and Britain since Saddam was expelled from Kuwait 11 years ago has crossed a new line, with a less secure legal and international foundation than the one which preceded it. If Bush pursues his war on Iraq, setting a disastrous global precedent for the principle of unilateral pre-emptive attack, it is likely to prove a watershed not only in the Middle East, but in the entire relationship between the US and the rest of the world. Despite the unease in Washington, the likelihood must nevertheless be that he will do so, with only the timing seriously in question. The administration is now so publicly committed to the destruction of the Iraqi regime that the political damage to Bush could be fatal if Saddam Hussein were still waving his rifle from a Baghdad podium in 2004.

But war on Iraq is not written in the stars - and it is even less inevitable that Britain will have to join it, as Tony Blair would doubtless want to do. Of course, the government has yet to make a case for war and the battle for public opinion will only begin in earnest when Bush decides to strike. If and when that happens, expect a string of terrifying revelations of previously unknown Iraqi weapons and real or imagined atrocity stories - of the type peddled during the 1991 Gulf war and 1998 Desert Fox bombing campaign - designed to win over the middle ground. But opponents of this war have already stolen a march on the government and their aim will be to achieve at least some British disengagement from a US attack, by sharply raising the cost to Blair of defying domestic opinion. Maybe Bush and Blair will get lucky. Perhaps the threat of invasion will trigger the coup that Saddam's terror has always prevented. Maybe the regime will collapse in good order, with barely a shot fired and general celebrations. But they won't be counting on any of it. Sooner or later, Tony Blair is going to have to decide whether he prefers to throw in his lot with a US Republican clique or represent the interests and convictions of his own people.

© Guardian Newspapers Limited 2002

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