The approach of war in Iraq has altered the international system irreversibly. Many familiar landmarks will be missing in the new world that is taking shape. Among them could be Tony Blair's premiership, which looks likely to be a casualty of the geopolitical shifts that are now under way.
For the past dozen years, Iraq has been a minor irritant in the system. Although its human costs have been high, the policy of deterrence and containment that has been in force since the first Gulf war has worked well. Saddam may have rattled the bars of his cage from time to time, but the notion that he is a major danger to world peace is laughable. Along with North Korea, Pakistan presents a far greater threat. If a US attack on Iraq produces upheaval in Pakistan, we could be faced with a failed state in which nuclear weapons are no longer under political control. The worst nightmare of anyone worried about the spread of weapons of mass destruction would then be a reality.
Saddam's weapons of mass destruction (if he has any, which he may well do) are a pretext. The decision to invade Iraq was taken many months ago, and the Bush administration is bent on much more than disarmament or even regime change. Its strategic objectives require the occupation of Iraq. The Bush administration has always viewed energy policy as a matter of national security. One of its strategic goals is to end US dependence on oil imports from Saudi Arabia, a regime it sees as colluding with terrorism. In the short to medium term of the next 20 years, the only way this can be done is by acquiring control of Iraq, which contains the world's second-largest pool of cheap oil. That would require a long-term US presence.
Whatever anyone says, therefore, the imminent war is very much about oil. Yet the Bush administration has no realistic idea of how it will secure Iraq's oil; its view of the aftermath of war is muddy in the extreme. Over the past few weeks, it has oscillated between talking of rule by an American military governor, on the model of postwar Japan, and promising an immediate transition to democracy. US relations with the Iraqi opposition parties have begun to unravel. There is a risk that the Iraqi state - a rickety structure cobbled together by departing British civil servants - will fracture and fragment in Yugoslav or even Chechen fashion. Some months ago, a swift move by the United Nations may have been feasible. It is not so easily envisaged today. Military rule may turn out to be the only solution, but it demands a degree of commitment and a willingness to accept casualties that the US has not demonstrated for decades.
Uncertainty about how to manage the aftermath of war reflects a deeper confusion in the administration's thinking about the future of the Middle East. There may be those in the administration who imagine that the US can take Iraq without unsettling the status quo in much of the rest of the region, but it seems clear they are no longer calling the shots. In a speech in Washington on 26 February, President Bush stated that the aim of war in Iraq was to bring democracy to the Muslim world. Reshaping the Middle East, he then declared, was part of America's mission to rewrite human history.
In most of the world, Bush's mix of realpolitik and evangelical uplift evokes mere contempt. In the Middle East, it augurs disaster. For much of the region, the choice is not between tyranny and freedom; it is between theocratic democracy and secular dictatorship. Democratic elections in a country such as Saudi Arabia would not bring about the triumph of "western values", as some members of the Bush administration fondly imagine. As in Algeria, they would result in the political victory of radical Islam. If any country embodies western values, it is Iraq, a thoroughly secular regime. The only Islamic country where secularism has been successfully combined with democracy is Turkey, in which America's effort to pressure the government into support for the war is strengthening Islamist forces.
We have been here before, and the precedent is an ominous one. Current US policy in the Middle East is a replay of the programme of national self-determination that Woodrow Wilson promoted in central and eastern Europe in the wake of the First World War. Now, as then, it has no understanding of the forces it is unleashing - ethnic nationalism then, radical Islam today. The result in the Middle East will be an upheaval as unmanageably destructive as that which shook central Europe in the interwar period.
The countries of the Middle East face a Malthusian squeeze: their populations will double in roughly 20 years. An attempt to install American-style democracy across a region where US power is already loathed will propel tens of millions of young people, many of them unemployed, into active support for radical Islam. The result can only be terrorism on an even bigger scale.
If Blair continues to maintain that war in Iraq will somehow tame the terrorist threat, the reason is that he has adopted a neo-conservative world-view in which history is on the side of US power. It is often said that, in backing the American attack on Iraq, Blair has proved that he is not the focus-group obsessive he sometimes seems to be, but instead a visionary leader capable of defying popular opinion when he believes he is in the right. Certainly, Blair has the courage that goes with a morally simple view of international relations. Yet I believe that miscalculations led him to his present position, not a clear view of where his moral certitudes should lead him. He misjudged the depth of opposition to the war in Britain and in his own party. He underestimated the difficulties of bringing the UN into line with the US position. He exaggerated the degree to which he could influence the Bush administration against the idea of unilateral action. Above all, he miscalculated US power and the scale of resistance to it.
Like most politicians, Blair has allowed his view of the world to be shaped by the conventional opinion of the past few years - that, with the collapse of communism, we have entered a unipolar world which will be dominated for the foreseeable future by the US. In this Whiggish philosophy, America not only possesses irresistible power; it embodies human progress.
But conventional opinion, as so often, is wrong. Militarily, the US is in a league of its own but, economically, it is increasingly vulnerable. Unlike Britain during its imperial period, which exported capital throughout the world, the US is the world's greatest debtor. This combination of military might with heavy dependence on foreign capital is bound to undermine America's ability to pursue a unilateral foreign policy. The first Gulf war was paid for by a coalition that included Germany, Japan and Saudi Arabia. The invasion of Iraq will have to be paid for by the US alone - hence the leaks emanating from the White House suggesting that the cost of occupation will be met by siphoning off some of the revenues from Iraq's oilfields. The US can ill afford its self-appointed role as "global hegemon".
If Blair has overestimated US power, he has also misjudged the depth of resistance to it. Conventional opinion has it that France and Russia will not use their power of veto to derail a second UN resolution: they will be brought to heel by a combination of bribes and threats to their economies and the damaging impact that unilateral American action would have on the authority of the UN. Maybe so, but in the volatile geopolitical environment that has emerged in the past few weeks, no one can be sure.
For President Jacques Chirac, the use of the veto would reinforce France's position as the dominant European power - and have the added advantage of destroying Blair, the chief spokesman of "new Europe" within the European Union. At the same time, France's status as a world power would be reaffirmed. It is true that a French veto may trigger a US attack on Iraq and render the UN practically irrelevant so long as Bush remains president; but that may be less permanently damaging than the UN's transformation into an instrument of American unilateralism. If the US finds itself mired in the internecine conflicts of postwar Iraq, France's stance on the war will be triumphantly vindicated.
Anticipating this outcome, President Vladimir Putin of Russia could also decide to use the veto. Faced with these risks, the US may well conclude that enough is enough. Urged on by hawkish advisers who counselled from the start against going the UN route and who view the disastrous political impact on Blair as a bit of collateral damage that the US can live with, Bush could decide to pre-empt a veto and launch an attack before the UN votes. Either way, the unipolar post-cold war world will be history - and so, I suspect, will be Tony Blair.
Thus, even before it has officially begun, the Iraq war has unravelled the shaky global settlement that was put in place by the Americans in the wake of the cold war. Nato and the EU are more divided than they have ever been; the future of the UN hangs in the balance. As in the 19th century, Europe and America are alien civilisations. It is against this background of a changed world that the unprecedented revolt took place in the House of Commons on 26 February. It was not just a vote on the war. It was also an expression of Labour's pent-up fury against the Blair government's neo-Thatcherite policies in health and education. Even more, it voiced a collective instinct that an era in world history - the short post-cold war era in which US power seemed invincible - is over.
Many analysts still forecast a swift, decisive war; but it is hard to see how that will rescue Blair if it is followed by a rapid slide into chaos. The geopolitical fissures that have been opened up by America's march to war yawn ever wider. Blair has said that history will judge him. It may do so sooner than he thinks.
John Gray's most recent book is The Silence of Animals.