Fergal Keane: There is only one way to defeat such hatred

'To track the killer you need to walk in his shadow, you cannot depend on missiles that rain from the sky'

It is 7am in Bogota, the capital of Colombia, and like everybody else waking up across the globe, I sense a world profoundly changed. The brief e-mail from London asked if I could write something that would somehow register the scale of the event. But that is beyond me. I do not have the language equal to this calamity. Last night the concierge asked if I would write a letter to the American guests on behalf of the hotel manager. His English wasn't up to the task. What should we say to them? I asked.

" Sympatico," he said. So we settled on the simple offer of comfort and an expression of sorrow. All day the Americans had hung around the television set in the bar, swerving between rage and despair. There was, above all, a sense of bewilderment. Why us? And to that there was no answer that would have made any sense at all.

The scale of the event? One commentator after another has spoken of Pearl Harbour and the American Civil War. But the events in New York and Washington and Pennsylvania exist in a different world. The comparisons with Gettysburg or Pearl Harbour are accurate only in the sense of indicating the degree of national trauma. But in the cold terrain of fact we should look instead to the humiliation of American power in Beirut in the 1980s or the slaughter of American forces in Somalia at the hands of Mohammed Aidid.

Both, in different ways, showed how small, ruthless groups can inflict catastrophic damage on a great power. People in Britain who have suffered the terror of the IRA will have some idea of the confusion thrown up by such horror; the instinct for vengeance is immediate but so, too, is a terrible sense of powerlessness: to attack whom and where and under what rules?

The giant roars but cannot find its tormentors. The terrorism of the IRA was ruthless but calibrated. It was, for the large part, nasty, tribal and small, with what the terrorists would call the occasional "spectacular". The murder of Lord Mountbatten and the bombings in Birmingham and Guildford evoked a national trauma, but nothing like that terrible Tuesday in America.

The slaughter in the US was of a different order: nihilistic, apocalyptic, a crime before which we are rendered speechless. So too will be the response, and in this lies a danger. The world in which Osama Bin Laden operates and from which he draws his support is a place of rage and alienation. Taking out the leader and his henchman will only answer an immediate need.

How does America deal with the long-term problem of being hated by people who are willing to take their own and others' lives? The short-term answer lies most crucially in intelligence. The Americans can learn a lot from the British in that respect. The reluctance to commit human resources in battle and intelligence post-Vietnam has been America's Achilles heel. To track the killer you need to walk in his shadow, to fight him you cannot depend on missiles that rain from the sky. By avoiding direct contact in the name of reducing casualties you risk an ultimate encounter in which casualties are much greater.

And none of this works without a political strategy. For too much of the period since the Second World War, American foreign policy has oscillated between isolationism and adventurism, between self-interest and moral crusading. The result has all too frequently been a policy of fire-fighting in which long-term strategic goals are ignored. All of this may seem a little ahead of the game when America is still counting its dead. But military retaliation is only the beginning of a very long war.

We may often find ourselves frustrated by America, angered by both its actions and its failure to act. But the values for which America stands – at its best and truest – are those of tolerance and fairness. You could fill many pages outlining where and how those values have failed, but in the long run we know that the slaughter in America was a wound against democracy and humanity. The war against terror is the new world war.

The writer is a BBC Special Correspondent