NEW YORK The 20th century was famously dubbed, by Time magazine's Henry Luce, "the American century," but the 21st century began with the United States having far greater global economic, political, cultural and military power than any other nation had previously held. Yet the United States was ambivalent about exercising that dominance, with many influential figures speaking and acting as if the rest of the planet were irrelevant to America's existence or to its fabled pursuit of happiness.

After terror attacks on Sept. 11 on the World Trade Center in New York and the Defense Department in Washington, there will be no easy retreat into isolationism for the United States, no comfort in the illusion that the problems of the rest of the world need not trouble it. Americans now understand viscerally the old cliché of the global village. A fire that starts in a remote thatched hut or dusty tent in one corner of that village can melt the steel girders of the tallest skyscrapers at the other end. It means the 21st century will be the century of "one world" as never before, with a consciousness that the tragedies of our time are all global in origin and reach, and that tackling them is also a global responsibility that must be assumed by us all. Interdependence is now the watchword.

The terrorist attack was an assault not just on one city. In its callous indifference to the lives of innocent people from 80 countries around the world who were in the buildings that were hit, it was an assault on the very bonds of humanity that tie us all together.

To respond to it effectively we must be united, and, out of the solidarity that the world has demonstrated with the victims of this horror, a unity may emerge across borders that will also mark the new century as different from the ones that preceded it.

Terrorism emerges from blind hatred of an "Other," and that in turn is the product of three factors: fear, rage and incomprehension - fear of what the Other might do to you, rage at what you believe the Other has done to you, and incomprehension about who or what the Other really is.

These three elements fuse together in igniting the deadly combustion that kills and destroys people whose only “sin” is that they feel none of these things themselves.

If terrorism is to be tackled and ended, we will have to deal with each of these three factors by attacking the ignorance that sustains them.

We will have to know each other better, learn to see ourselves as others see us, learn to recognize hatred and deal with its causes, learn to dispel fear, and above all just learn about each other.

As this lesson is absorbed and applied, the 21st century could yet become a time of unprecedented mutual understanding. A world in which it is easier than ever before to meet strangers must also become a world in which it is easier than ever before to see strangers as no different from ourselves.

The terrorists failed to see their victims that way: They saw only objects, dispensable pawns in their drive for destruction. Our only effective answer to them must be to defiantly assert our own humanity - to say that each one of us, whoever we are and wherever we are, has the right to live, to love, to hope, to dream, and to aspire to a world in which everyone has those rights.

It would be a world in which the scourge of terrorism is fought, but so also the scourges poverty, famine, illiteracy, ill-health, injustice and human insecurity, a world, in other words, in which terror will have no chance to flourish.

That could be the world of the 21st century, and it could be the most hopeful legacy of the recent horror.

The writer is a senior United Nations official and author most recently of the novel "Riot." He contributed this personal comment to the International Herald Tribune.

Copyright © 2001 The International Herald Tribune