English, of course, articulated my American identity, the world I was born into. Spanish represented a kind of bridge, a way of crossing over into a new but knowable place. Years before a physical bridge existed, my wife and I took a ferry across the Parana River in southern Paraguay to Posadas, Argentina, where she bought me a paperback collection of the poetry of Borges, the first writer outside my own American culture whose work I tried to understand (I'm still trying). Guarani was different. It was local, rural, an impenetrable thicket. The language belonged to Paraguay, and it guarded its secrets. Only a few times -- listening to a Chaco War veteran describe his own personal horror in the desert; or drinking mate with a farmer while it rained too hard to go to the fields; or sharing a glass of cane whiskey with a restless dreamer planning a horse race to make travel money
-- did I come close to the wall that kept me outside the culture their Guarani protected.

It's no accident that the one place where the three languages came together seamlessly was a dream. Outside of dreams, it's the grinding at the edges where cultures intersect that has fascinated, even obsessed me. It's probably the reason I joined the foreign service. It became the primary material of my writing life. And it started a long way back, years before Paraguay. It started when I did.

My parents came from very different American places. My mother's family in Pennsylvania were rural. They fished and hunted. They were good with machinery; they fixed tractors, lawn mowers, cars; anything with a motor. They played country music on the stages of fire halls and bars. They were Protestant, and mostly laconic, and suspicious of the kind of people who lived in my father's world, which was urban and in specific ways antithetic to my mother's. My father's family worked in factories, for the most part. They were Catholic, and in Niagara Falls they lived in neighborhoods still divided by ethnic groups (you could be Irish and live in a Polish neighborhood, you could be Lebanese and marry an Italian, but you knew who you were regardless, and you knew who they were). My father's people talked more than my mother's family did, and they spoke a different American idiom. They told stories. Some of the stories they told were true; most of them were entertaining. Their music was swing, their style was looser. On the gurney at Niagara Falls Memorial Hospital in the middle of a heart attack, when medical personnel asked my father whether he had any allergies, he responded, "Just country music."

It's too much of a stretch to say that my parents came from different cultures. The Shumways and the Jacobs inhabited, bespoke, and defended different forces of the same big, noisy, messy and conflictual American culture. But it's not too much to say that watching the complicated intersection of those different dimensions of American life is what drew me both to the foreign service and to writing about borders and the people who cross them.

We lived in Niagara Falls but spent a lot of time in Pennsylvania, on my grandparents' farm in Towanda. Moving back and forth between one place and the other was a lot like crossing a border. One consequence is that, in a real way, my brothers and I grew up comfortably bicultural. Because we had to, we learned to understand both worlds, to speak both American idioms. We listened to the music, read the road signs, stood at the intersections where the two families did not quite come together.

All of that helped. Beginning with two years in Potrero Yapepo, in Itapua, Paraguay, I lived a series of useful cultural dislocations. They were useful because they unsettled my sense of identity, which in my case seems to have been a good way to jump-start the imagination. In Paraguay, I bought a small portable typewriter and began writing stories set in that country almost before I could speak the language(s). Imagining the lives and circumstances of people whose experience was so remote from my own was an almost unbearably arrogant thing to attempt, and I knew it. I failed much more often than I succeeded. But I thought when I began and think more fervently now that imagining other lives, distinct realities, experience foreign to one's own, is not only possible, it can be the obsession of a life.

There are ways and ways to approach a culture foreign to one's own, and some of them are full of potholes. The complexities involved in trying to understand and represent in words a foreign culture stand out with sometimes painful clarity in the writing of Joseph Conrad. It's hard to argue with the Nigerian novelist Chinua Achebe's bitter indictment of the author of Heart of Darkness as a racist, but it seems to me that there is more nuance and more valuable ambiguity in some of Conrad's work than Achebe is willing to grant him.

In fact, "Karain: A Memory" shows another Conrad. In "Karain," the narrator, a white gun-runner, relates the story of a Malay tribal leader with a complex and shifting set of emotional reactions ranging from powerful sympathy to a distancing condescension that falls back on the easy assumptions of English superiority. The story moves giddily through a series of transitions the narrator makes between those conflicting extremes. When it's over, the narrator brings the story to what seems, on first read, a stolid, reassuring London scene speaking for the triumph of British civilization over the imaginative exuberance, the flash and color and exotic excess of "the East." But there has been too much back-and-forth movement in the course of "Karain" to fix the story on that bustling, self-satisfied London street. Here is one way of constructing the world, Conrad's narrator subtly suggests, and there is another, and the truth of experience is to be found in the nervous traffic between them. The reader walks away from "Karain" wobbling and wondering, drawn into the cultural confrontation in a profoundly unsettling way.

What is it about Conrad that allows him to stand, if not with a foot in another culture, then right up next to it, observing what's there to observe with an intelligent and curious eye? One of the most perceptive Conrad critics, Edward Said, talks about the "aura of dislocation, instability and strangeness" in the writer, the result of Conrad's exile and alienation, his "loss of home and language." Conrad's experience was extreme. It inflicted permanent changes on the man. He left and lost his home, his language, and his culture for good. There was no going back to Poland. Writing in Polish was useless. With an effort of will that defies comprehension, the sailor-writer-would-be-adventurer grasped for and appropriated a new home, an alien language, a foreign culture. One effect of doing that was to make him intensely aware -- some might say neurotically aware -- of what we would probably today call cultural relativity.

In the United States, we sometimes speak almost casually about reinventing ourselves. The possibility of reinvention has been a staple of our sense of who we are beginning with the discovery-cum-conquest of the American continent. It runs consistently through our culture from the Pilgrims' conviction that they were establishing a "city on a hill" through Emerson's most provocative essays to Bob Dylan's changing the changes album by album. Often, though, we say we have reinvented ourselves when what we really mean is that we've changed something about ourselves: our job, or where we live, the way we dress or pay our bills or entertain ourselves. It's easy to forget that reinvention begins with an act of destruction: The old self has to go to make room for the new one. Conrad knew that because he lived it. And he lived it because he had to, not because he thought it would be an interesting intellectual exercise.

Peace Corps and the foreign service do not come close to that kind of profound experience of remaking oneself. Every time I left the United States, I figured I was coming back. Although I acquired new ones, I kept my own language. I stayed plugged into my own culture; with today's technology, and the noise it generates, it's harder to unplug than it is to stay connected. So despite living outside of my home culture for 15 years, I was not reinvented. Other valuable things did happen to me, though. In the course of living and working in other countries, I was dislocated. I was challenged and provoked. I was sometimes humbled and frequently surprised. I wasn't reinvented, but I think it's fair to say I was enlarged.

Writing fiction set in the places that I lived in, I was drawn to certain kinds of narrators. Tourists of any kind, including those on cultural junkets, did not interest me much. I looked for people whose voices had the range to express a different sort of engagement with the culture in which they found themselves. Journalists, especially foreign correspondents, were particularly attractive because reporters tend to be curious and irreverent and to have a strong sense of outrage, however well channeled they keep it. They spend their time trying to figure out what's going on in a place they were not born in. In order to write an accurate story, they have to decipher the cultural codes. They move on, but while they're there, the good ones -- and there are lots of good ones -- engage intensely with the country they cover.

Temporary or permanent expatriates, certain (but definitely not all) diplomats, aid workers and missionaries, adventurers and spies -- all of them offer the right kind of character for writers interested in the intersections of cultures. One thinks of the cast of characters from Graham Greene's many novels. For an American writer, the expats are in a sense the easy part of the mix. At least it is relatively easier to depict them with the combination of sympathy and accuracy that good fiction demands regardless of its subject matter. The American characters come from the writer's own world of experience. Observed outside their element, they stand out.

Much trickier, and more likely to fail in the attempt, is the development of characters from the countries and cultures in which the story takes place. Greene was aware of the difficulty of doing imaginative justice to the characters he developed that were not British. Writing about the Mexican policeman who tracks down the whiskey priest in The Power and the Glory, he frankly says he made up the character from whole cloth. The novel needed the intense, rigorous, and puritanical lieutenant to balance the sloppy, weak, and dissipated priest. The author's trip through Mexico did not turn up a human model, so he worked from scratch but was not, one senses, completely satisfied with the result.

Writers like Achebe and Said have pointed out how easy it is to "orientalize" a foreign culture, to use it as an exotic background on which to paint characters from one's own culture. When that happens, the appropriated culture at best provides local color. At worst, the story dehumanizes people in the horrific way that Achebe asserts Heart of Darkness as doing through Marlowe's depictions of black Africans.

There's no single word ample and accurate enough to describe the world that has succeeded the colonial era whose bloody end Conrad's work foreshadows. Postcolonial? Sure. The world we inhabit is certainly that, but the word suggests where we've come from more than where we're going. It doesn't do justice to the depth of change in people's perceptions that has taken place since, say, the 1950s. There are days when it's depressingly difficult to remain aware of that change because of the violence that keeps happening, too often, in too many places. But the colonial worldview is dead regardless. Those who upheld it and those who resisted it are dead. Something else will take its place.

It's probably too soon to give it a name. We're in a transitional stage, and calling it the postcolonial era will have to do for a while longer. But there are encouraging signs that what emerges will be better than what we're leaving behind. In the case of literature in English, it has already been incalculably enriched by writers from Africa, from India, from the Caribbean and elsewhere.

Less noticed, less important but still worth thinking about, is another change that's going on at the same time. When they travel outside the United States, American writers are trying to do imaginative justice to characters who are not American: the Paraguayan cotton farmer, the Honduran human rights activist who hides incriminating documents in a broken refrigerator, the Kenyan investigative journalist with scars and secrets, the Spanish intelligence officer whose father entertained tourists with card tricks for shots and cigarettes.

Before she died in a plane crash, the American novelist and aid worker Maria Thomas worked with passionate intensity to describe the complex interactions between Africans and Americans by creating characters from both cultures of equal complexity and credibility. At its best, Thomas' fiction radiates that elusive combination of sympathy and accuracy that Greene was conscious of needing in his own work. Other writers are trying to do the same. Norman Rush, Paul Eggers, and Marnie Mueller all work to do imaginative justice to relationships across cultures in the postcolonial world.

The 19th-century English critic Matthew Arnold once wrote that to truly appreciate the literature of one's own culture, it was necessary to know that of another. He was talking about how important it was to know French to understand English. Today, the notion of paying careful attention to a culture not one's own is even more compelling. It's also more of a challenge. The Borges I pick up tonight is not the Borges I read while living in a converted meat market in Encarnacion. Fortunately, American writers writing fiction set in cultures not their own have a tremendous resource available to them, the literature of the countries about which they want to write. Maybe it's true that wherever you travel, the way to the writing is still through the reading.