Britain's Tony Blair says the attack heralds a battle against freedom and democracy. Germany's Gerhardt Schroeder says it is an act of war against democracies. France's Jacques Chirac says this act must not go unpunished. Both the expressions of sympathy and calls for revenge will increase by the hour in coming days as the unbelievable becomes credible and the sheer numbers of casualties sink into the world's consciousness. Whatever happens, the horror will remain carved into the granite blocks of history forever. But can such acts be truly avenged, or more importantly, foreseen and prevented? Violence begets violence but do those who strike the first horrific blow vent the suffering of their oppression or are they brain washed by a fool's paradise of martyrdom?

Those questions will no doubt be flogged ad infinitum in coming days, weeks and years as the rich and powerful of the current world order batten down the hatches to protect themselves against the suicidal irrationality of those who think they can fight injustice by causing grievous harm to the innocent people of their imagined enemies.

Whatever the twists and turns of the future, the challenge right now is to absorb into our consciousness the unimaginable hate of those who flew the airlines and their backers as well as the unprecedented devastation they caused. That is a tall order in such a short space of time.

For Europeans, whose afternoon and evening on that deadly day were drenched in puzzlement and incomprehension, the challenge of understanding such acts is like scaling treacherous alpine peaks. Some manage to reach the summit, many other die because of careless preparations or freak events of nature. America is the leader of the Western world; America unilaterally takes decisions that many Europeans do not support; some manage to live with them; others fear their outcomes.

Suddenly, the dead and wounded of New York and Washington have clobbered Europeans with the realization that whatever their opinion about America's decisions, the leader is vulnerable and cannot be left to carry the burdens of leadership alone.

That is already apparent in the chief reactions on the streets as well as corridors of power. The overwhelming feeling among Europeans despite fears for their own safety is one of solidarity with America and unity with the pain of its people and the anger of its leaders. None of Europe's leaders has spoken idle words. Each means what he says when he says that no stone can be left unturned in bringing the perpetrators of the attack not only to justice, but to exemplary justice.

The attack's planners may feel astonished at the world's collective outrage because unlike the assailants, themselves, those supporters must include sophisticated analysts who thought that some might see the attacks as reactions to injustice. Apart from a handful of people in Palestine and a few other Arab countries who rejoiced briefly, no representative of any community anywhere in the world has expressed approval for the attacks or for its planners.

Europeans see themselves to be at high risk. All stock markets in Europe plunged downwards on Tuesday, some by nearly 10%. Security has been heightened at all airports, rail terminals and public buildings. A vast hunt is already underway to unearth anomalies and clues and, of course, to review intelligence information that might have been neglected or put aside for later analysis.

The cabinet of almost every Western European nation met in emergency session on Tuesday and crisis management committees have been activated. The defense forces of several countries have been put on high alert. NATO, based in Belgium, has activated its crisis management teams and is ensuring that its peace-keeping activities in Kosovo, Bosnia and Macedonia are not disturbed. The SHAPE headquarters in Belgium, which implements America's military activities within the NATO context, are on full alert.

Europe's governments are looking towards Washington for information and guidance about the riposte to these attacks. Nothing will be done by Europeans outside a unified response by America and its allies. So far the quiet and steady anger of President George W. Bush is also that of the Europeans. But things may start to look different by Wednesday and Thursday, when the casualty toll becomes clearer and if stock markets and airlines remain silent.

So far, European leaders and commentators are insisting that keeping a cool head in the face of this provocation is the only way to get to grips with what has happened and to identify the culprits. Then the full force of Western might must be brought to bear as quickly as possible.