The Shadow of Terror: A darkness fell on 11 September. Have we the vision to defeat it?

Three-and-a-half months after the deadliest terrorist outrage in modern history, there is more justification than usual for indulging the journalistic urge – traditional at this time of year – to look back and take stock. The first phase of the American-led "war on terror" is approaching a conclusion, although the chief suspect remains at large. But what, if anything, has been achieved?

Special report

The shadow of terror: Three months on

Three-and-a-half months after the deadliest terrorist outrage in modern history, there is more justification than usual for indulging the journalistic urge – traditional at this time of year – to look back and take stock. The first phase of the American-led "war on terror" is approaching a conclusion, although the chief suspect remains at large. But what, if anything, has been achieved?

The fairest verdict at this point would seem to be: so far, so good. Afghanistan is a better place today than it was on 12 September, after a surprisingly brief military operation masterminded by the Americans. The Taliban regime has been destroyed, and, in that country at least, the al-Qa'ida network of Osama bin Laden has been devastated. But if events in Afghanistan offer hope, they also offer temptations that must be resisted.

Fewer people than before now dispute that America was right to launch this war, although the consequences may take years to ripple around the world. But military success in Afghanistan is no reason to send B-52s and the Marines against other regimes that Washington does not care for. Nor should it use this war as a pretext to settle old scores in Iraq – not, at least, without proof, completely lacking thus far, that Saddam Hussein had a hand in the events of 11 September.

No one country, however powerful – nor even the group of rich countries that Tony Blair is fond of referring to as the "international community" – has the moral right to act as judge, jury and executioner. Military force is like a drug – the more it is used, the greater the risk of addiction. And each new time it is used, the number of innocent civilian deaths – "collateral damage" in bland Pentagon-speak – increases. Already, the total of unintended casualties in Afghanistan alone may approach, or even exceed, the 3,000-plus who died on 11 September. A reckless prosecution of the anti-terror offensive beyond Afghanistan would invite the risk that the war will be perceived in many parts of the world simply as one of terror against terror. This danger appears to be understood in London and Paris, but not yet in Washington.

There is, moreover, an equally powerful practical objection to a wider, purely military offensive against terrorism. On its own, such a strategy can never succeed. All it will create is a yet more burning desire for revenge, stoking the fires of fanaticism still further. And in a world where nuclear and biological weapons proliferate, that revenge may, next time, take an even more lethal form than crashing aeroplanes into skyscrapers. This year has, after all, emphasised again that strategic genius is not the exclusive preserve of trained military minds.

In Washington, the personification of this war is not the cautious Colin Powell, so beloved of us Europeans, but the crusty, shoot-from-the-hip Defence Secretary, Donald Rumsfeld, squinting at the world through suspicious and hawkish glasses. Rumsfeld is fond of referring to the campaign against terrorism as "draining the swamp". The metaphor is a striking one, but he and his supporters would do well to think it through. You do not drain a swamp by systematically exterminating everything that you consider to be a mosquito; you do so by removing the conditions and the environment that allow the mosquitoes to breed.

Terrorism is the scourge of our times not simply because random groups of wicked people have conceived an irrational desire to slaughter Americans and, as President Bush so absurdly puts it, to "destroy our way of life".

Terrorism is born of specific grievances. It is not about poverty; witness the backgrounds of those angry young men who boarded the four American aircraft in September. For too many people in too many countries, the political and economic systems under which they are forced to live offer no prospect of justice, human rights or self-expression. They are left with a burning anger and resentment, and this all too often explodes into violence.

In the Middle East, these grievances are sharpened by the failure of Islamic culture to come to terms with the modern world, by America's unquestioning support of Israel, and by Washington's support of repressive regimes in order to secure a reliable supply of oil. The Taliban may have provided sanctuary for Mr bin Laden. But the epicentre of this crisis is not Afghanistan: it is his native Saudi Arabia and, to a lesser extent, Egypt.

For all the military success in ousting the Taliban in Afghanistan, these are issues that remain unresolved. It is vital that they continue to be discussed in the months, years and decades ahead, when the political focus reverts to more prosaic domestic debates. But some points are beyond dispute. The "war against terrorism" will never be won on the battlefield, any more than the Cold War was. Nor can it be won by covert action and intelligence alone, nor by the diplomatic, financial and economic sanctions of which Mr Bush speaks. Victory will require true statesmanship, a realisation by the United States and its friends that their long-term interests are the same as those of rest of the world; and it will require a generosity to match.

This, if it happens, will be a process of many years. In the meantime, we will continue to live in the shadow of terror.