Years ago, people of my generation sometimes would ask one another, 'Where were you when JFK was assassinated?'" Now, in 2002, all generations in almost all countries can ask, where were you when the planes struck.

The answers almost always sound so insignificant. In the case of the CTV London bureau, I was sitting in a restaurant, breaking the news to a largely broke young Canadian freelancer that there was not a lot of extra work available in London at that time.

My telephone rang and a friend asked, "Are you watching television."

She told me that a plane had struck the World Trade Center but nobody knew yet whether it was a deliberate act or an accident. I left the restaurant on the run, leaving a half-eaten lunch and the still broke freelancer. I arrived back in the office to learn that a second plane had struck. All doubts vanished with the explosion. One plane crashing into one tower could be a terrible accident. Two planes in two towers was unprecedented terrorism. And the moment the towers began collapsing, the realization hit. The world's greatest superpower had been struck a terrible blow.

It would consider it an act of war. And somebody would pay.

British television showed the images again and again, and inevitably, the question. If in New York, why not here as well? The instant rumour-mill began churning, the most prevalent thought being that some of London's taller buildings may be targets as well, perhaps even the Parliament buildings themselves.

Late afternoon, a large building in the east end of London had been evacuated. Immediate speculation was that a hijacked plane was on its way there. From my office, you can just make out the building in the distance. I watched it, transfixed, until I got the news that a fire alarm had gone off by accident.

Security all over the city was tightened. And almost immediately, the street in front of the American embassy was blocked with concrete barricades. They are still there to this day, a reminder, possibly permanent, that the world was facing a new threat with few, if any, limits.

All over Europe (perhaps all over the world), American diplomats began travelling with protection. People who had intended to travel stayed home. Flights were being cancelled. People who were still travelling, faced long lines and delays as security personnel carried out minute searches.

Within 24 hours, the British Prime Minister Tony Blair went on television here and said, "The world now knows of the evil and capability of terrorists. It's an attack on all democracies in the world."

The NATO General Secretary George Robertson said, "What happened to the United States could have happened to any of the other 18 members (of the alliance)."

And perhaps reflecting a sentiment spreading across the globe, German chancellor Gerhard Shroeder said, "The attacks are a declaration of war against the whole civilized world."

Less than 72 hours after the planes struck, there was a period of mourning all over Europe. For one minute, nations that are home to 800 million people ground to a halt. Even here in London, one of the world's busiest cities, bus drivers, taxi drivers, people managing businesses, shoppers, all stopped what they were doing to think for a moment of what had happened.

And in many world capitals, leaders and their armed forces were working out who was responsible.

Several weeks later, I was in the region of Afghanistan covering the war. I would spend two months there, much of it in areas that can only be described as some of the most miserable in the world.

The vicious Taliban regime was overthrown. Its protected friend, and the individual held directly responsible for organizing the September 11 attacks, disappeared. Today, Osama bin Laden may be dead or he may be hiding out somewhere in the region, but the fervent hope of his victims is that he has been rendered powerless.

Still, the consequences of Sept. 11 endure. One can always hope that such an event can somehow teach a benevolent lesson, inspiring people to react in such a way as to make the world a more peaceful place. But the lesson may not be so sanguine.

There is more talk of war. This time, the target may be Iraq, and the justification goes back to those crashing towers. Prime Minister Blair has called Saddam Hussein the leader of an evil regime who is amassing weapons of mass destruction. And something must be done to stop him.

If there is an invasion, it would not be so much a response to what happened last September 11th, but to prevent, we are told, the possibility of a similar event from happening.

One year on, the images and the lessons of that day seem no less vivid. Something has changed in the world, just as irrevocably as the New York skyline.