There was the afternoon in June 1967 that I spent climbing up the Golan Heights, watching Israeli soldiers pull defeated Syrian troops out of foxholes while the smoke from artillery shells still rose from the soil. Then, days later, I stood at the Allenby Bridge and watched shattered Palestinian families by the thousands cross into Jordan and exile.

There were the two occasions on which I was arrested by the KGB,and threatened with expulsion from the Soviet Union, for the crime of photographing demonstrators in Moscow. When I later complained to a KGB official who masqueraded as a Soviet diplomat that Russian correspondents were free to cover demonstrations in the U.S., he smirked and replied amid howls of laughter from his subordinates: "We will see to it that you are free to cover demonstrations There were the months in which I was followed ostentatiously everywhere. I went in Cairo by a secret police agent, then awakened repeatedly by 3 AM phone calls from someone who never spoke, a way of letting me know I risked serious trouble if I kept reporting on the former Nazi rocket scientists who had been hired by Egypt to build missiles for use against Israel.

There were the weeks of dodging bullets, sometimes by inches, during the Iranian revolution, and the searing experience of seeing one of my close friends, Joe Alex Morris Jr. of the Los Angeles Times, killed alongside me on the penultimate day of the revolution. For months afterward I relived that experience in a kind of obsessional waking nightmare.

There was the white-knuckle ride aboard a Soviet helicopter that brushed mountaintops in Afghanistan, firing off flares to try to divert any heat seeking missiles that mujahedeen fighters below might fire at us. All the while I wondered if I would suffer the ignominy of being killed by an American weapon in a Soviet war machine.

There was the Afghan official who, at the end of a long interview on a now-forgotten subject, turned to me and addressed an earnest entreaty: "Tell me, what percentage of what I've just told you do you believe?"

There was the near-fatal experience on an Iranian military transport plane at Bandar Abbas, carrying 77 coffins of people killed when the U.S. Navy mistakenly shot down an Airbus airliner. The coffins, improperly strapped down, began toppling over and bodies spilling out as the plane sped down the runway. The pilot barely stopped in time to avoid a takeoff that he later admitted would have ended in a crash.

There was the day I followed Queen Elizabeth II on foot to the sources of the Blue Nile in the Ethiopian highlands, with Prince Philip flailing at the accompanying photographers with a riding crop. That same evening, at a regal banquet hosted by Emperor Haile Selassie, I became memorably so used on tej, a brew made from fermented honey whose potency I had seriously underestimated.

There was the stunning scene on an evening in 1991 when I witnessed thousands of Kurds stumbling in a broken line down a mountainside in Turkey from towns and villages in Iraq, driven out by poison gas attacks by Saddam Hussein's army. Then the heart-breaking days in which they huddled on open ground, pelted by rain and beginning to die by the scores, before American cargo planes brought deliverance from the sky.

There is the still-fresh image of houses burning in Kosovo, sullen and defiant Yugoslav troops departing, scenes of massacres the water dried up and the toilets did not flush for four days.

Can it really be 40 years since I stumbled, wide-eyed and unprepared, into the sometimes funny, sometimes tragic, mesmerizing world of the foreign correspondent?

I had gone to Rome in 1961 for what was to be a year-long adventure in Europe, a carefree lark between serious career moves. Although I have had fleeting sojourns in Chicago and Washington since then, I have, in a sense, never left. "Abroad" became my home.

>From Rome I eventually moved on to postings in Cairo, Belgrade, Moscow, Brussels, Nairobi, Berlin and London. The datelines on my stories have come from 80-odd countries on four continents, as far apart as Spitzbergen in the Arctic Circle and the Falkland Islands in the South Atlantic.

It wouldn't be true to say there has never been a dull moment, but for the most part this has been a privileged life on the front line of history. I have covered eight wars, the revolution in Iran, civil conflicts in Northern Ireland and the Basque country, the death of two Popes and the election of two others, the fall of the Berlin Wall, the death of Princess Diana.

I have even endured countless Michelin three-star meals, and put numerous luxury hotels to the test, all in the line of duty. And I once stayed in a hotel in Kampala, Uganda, in which the only running water was a greenish slime that came from fire hoses that some obliging Congolese prostitutes staying in the hotel helped me drag to my room to fill the bathtub. Sheets that had not been changed in weeks were black with grime and littered with the remains of bedbugs that presumably had succumbed to the unsanitary conditions.

Before I left America, I had at the age of 25 covered for the Arkansas Gazette what I was confident would be the biggest story of my career, the Little Rock school integration crisis. I could not have imagined what lay ahead.

I began writing this article in early September, with a brief to describe ways in which the world has changed since I first came abroad. After the attacks on the World Trade Center and Pentagon, every other development of the last 40 years seems to recede into a shadowland of insignificance. Yet. the changes that preceded September 11 are still with us, and it is not an easy task to draw a coherent picture of how they have made the world either better or worse. I can only describe what I have seen.

The 100-year cycle that recently ended has rightly been proclaimed the American Century, and the apex of that glorious period in our history more or less coincided with my arrival in Rome. America was then far more admired in the world than it has been in recent years. The memories of World War II, and of the turbulent years that immediately followed, were still fresh. The U.S. had saved the world from the Nazi menace, then from Communist attempts to subvert Europe after the war. What a great, idealistic nation we were. What enormous gratitude we inspired.

More importantly for a young man who had accepted a penurious salary to work on a small American-owned newspaper in Rome, this was a wonderful time to live abroad because the dollar was king. I could dine in some of the better restaurants in Rome for $5 a night or less, and that wasn't just because everything was cheaper 40 years ago. It was mainly because of the immense purchasing power of the dollar, now sadly just another of the world's leading currencies.

Rome was not then the rich, bustling, chaotic city it is today, but the more tranquil capital of a poor country still recovering from the war. Few people had cars; most of the cars were tiny Fiats that seemed to be powered by lawnmower engines and Italians careened through the streets on noisy motorscooters even more than they do today. It was a glorious place, and Italy remains for me a kind of spiritual home.

It was a less-crowded world then, and to me that is one of the most significant changes of the last 40 years, or at least as significant as the technological revolution that is still unfolding. When I arrived in Rome, the world population stood at 3 billion. Today it is 6.1 billion and 50 years from now it is projected to reach 9 billion or more. When I moved to Cairo in 1964, its population was 4 million and the city was overcrowded. Today it is 13 million. Egypt's population was 28 million in 1964, 63 million today and projected to reach 80 million by 2017. Its people live almost exclusively along a thin green strip on either side of the Nile in an otherwise desert country, a terrifyingly narrow hold on existence.

Few developments have been more profound in their manifold implications than the explosion in world population. Degradation of the environment, global warming, Third World poverty, mass migrations from poor to rich countries, increasingly worrisome shortages of water and lack of social cohesion are all related in one way or another to the fact the number of people in the world exceeds the world's ability to cope. It is a story that we in journalism tend to cover in piecemeal fashion, seldom pulling together the disparate threads of this burgeoning problem and tracing them back to a common root.

At moments such as the current one, it may be easy to forget ways in which the world has changed for the better. Yet the Soviet menace is gone, Europe is whole and free again and undoubtedly the most exhilarating experience of my career came on the night of Nov. 9, 1989, when I went to Checkpoint Charlie in Berlin and found the world had turned upside down. East and West Germans were embracing, and people were sharing champagne with East German border police who only days before would have been prepared to shoot them. The Berlin Wall had fallen.

That night the world became a better place. Yet human progress has never been traceable on an even trajectory. AIDS, which didn't exist in 1961, is today devastating an entire continent, Africa. Organized crime in 1961 meant mainly Sicilian and American mobsters, but that was before the mob came to globalization; now organized crime is a worldwide phenomenon and a $1 trillion-a-year business. Drugs were just beginning to arouse serious concern when I left the U.S., and were not something I can remember people in Europe discussing at all.

Two years in Africa gave me an appreciation of Third World poverty at its worst and of the resilience of people who have not been favored by nature or history. When I left Africa in 1981, I wrote a series of articles that forecast a gloomy future for the continent until at least the end of the 20th century. Twenty years later, the gloom has lifted only in a few places.Africa has had its Nelson Mandela, but it has also had Robert Mugabe. It is still burdened with corrupt, incompetent and sometimes psychopathic leadership, as well as tribal division that, perhaps more than anything else, ensures the struggle for a decent life will be long and hard.

Europe, where I have lived most of my life, has undergone a change over the last 40 years that has been so slow and fitful that people tend to ignore its significance and take it for granted. But it is little short of a miracle that people who have fought each other throughout their history, and engaged in two ruinous world wars in a space of 21 years, have forged a community of nations that almost guarantees they will live forever in peace I end my career, not as I would have wanted, but amid the emotional wreckage of a newly shattered world. I spent my childhood as a distant witness to the violence of World War II, and the world has not ceased to be a violent place since. The things that frighten, worry and challenge us change over time, and sometimes slip blissfully into chambers of forgetfulness. But they are an ineradicable ingredient of modern life, as has now become all too tragically evident.

Terrorism had not, so to speak, been invented in 1961 when I went abroad. Even before September 11, for all the tragic consequences that ensued from it, terrorism was a phenomenon that most of us watched from afar it but spared a sense of immediate vulnerability to it. That form of terrorism had a political purpose, to force its victims to negotiate with its perpetrators, and that implied certain boundary lines that could not be crossed.

The terrorism that Osama bin Laden has unleashed is terrorism in a purer form negotiated. Only the destruction of its enemies will satisfy its appetites.

That is undoubtedly the most startling, the most shocking, change of the last 40 years scale none of us could have imagined. They have truly changed the world and, with their appearance, America's curiously alternating history of engagement with the world, then withdrawal from it, may have gone forever. Or so I fervently hope.

American ambivalence toward the rest of the world has been present through much of the nation's history and manifested itself clearly after the Cold War. Many Americans enthusiastically embraced the notion that, with the Soviet menace gone, it was time for the U.S. to focus on its own problems; it couldn't be the world's policeman, or keep bailing out ungrateful foreigners.

After the Falklands war between Britain and Argentina, I encountered an American family living in that far-off corner of the world who in a sense represented in microcosm the American yearning to shut out the world. Spooked by the conviction that a nuclear war between the US and Soviet Union was inevitable, they had gotten out a map and searched for a place to live where they could be safe when Armageddon arrived.

They had hit on a spot they had never heard of, the Falkland Islands, and had moved there just months before war came. As Argentine troops invaded the islands, then Britons stormed ashore to liberate them, this family hunkered down amid the gunfire and learned something that other Americans are having to learn now: The US and its citizens cannot live in isolation from the world and its problems. We are all one.