Dear America: This is a difficult letter to write, because I'm no longer sure who you are.

 Some of you may be having the same trouble. I thought I knew you: We'd become well acquainted  over the past 55 years. You were the Mickey Mouse and Donald Duck comic books I read in the late  1940s. You were the radio shows - Jack Benny, Our Miss Brooks. You were the music I sang and  danced to: the Andrews Sisters, Ella Fitzgerald, the Platters, Elvis. You were a ton of fun.

 You wrote some of my favourite books. You created Huckleberry Finn, and Hawkeye, and Beth and  Jo in "Little Women," courageous in their different ways. Later, you were my beloved Thoreau, father  of environmentalism, witness to individual conscience; and Walt Whitman, singer of the great  Republic; and Emily Dickinson, keeper of the private soul. You were Hammett and Chandler, heroic walkers of mean streets; even later, you were the amazing trio, Hemingway, Fitzgerald, and  Faulkner, who traced the dark labyrinths of your hidden heart. You were Sinclair Lewis and Arthur  Miller, who, with their own American idealism, went after the sham in you, because they thought  you could do better.

 You were Marlon Brando in "On The Waterfront," you were Humphrey Bogart in "Key Largo," you  were Lillian Gish in "Night of the Hunter." You stood up for freedom, honesty and justice; you  protected the innocent. I believed most of that. I think you did, too. It seemed true at the time.

 You put God on the money, though, even then. You had a way of thinking that the things of Caesar  were the same as the things of God: That gave you self-confidence. You have always wanted to be a city upon a hill, a light  to all nations, and for a while you were. Give me your tired, your poor, you sang, and for a while you meant it.

 We've always been close, you and us. History, that old entangler, has twisted us together since the early 17th century.   Some of us used to be you; some of us want to be you; some of you used to be us. You are not only our neighbours: In  many cases - mine, for instance - you are also our blood relations, our colleagues, and our personal friends. But although  we've had a ringside seat, we've never understood you completely, up here north of the 49th parallel.

 We're like Romanized Gauls - look like Romans, dress like Romans, but aren't Romans - peering over the wall at the real  Romans. What are they doing? Why? What are they doing now? Why is the haruspex eyeballing the sheep's liver? Why is  the soothsayer wholesaling the Bewares?

 Perhaps that's been my difficulty in writing you this letter: I'm not sure I know what's really going on. Anyway, you have a  huge posse of experienced entrail-sifters who do nothing but analyze your every vein and lobe. What can I tell you about  yourself that you don't already know?

 This might be the reason for my hesitation: embarrassment, brought on by a becoming modesty. But it is more likely to be  embarrassment of another sort. When my grandmother - from a New England background - was confronted with an  unsavoury topic, she would change the subject and gaze out the window. And that is my own inclination: Mind your own  business.

 But I'll take the plunge, because your business is no longer merely your business. To paraphrase Marley's Ghost, who  figured it out too late, mankind is your business. And vice versa: When the Jolly Green Giant goes on the rampage, many  lesser plants and animals get trampled underfoot. As for us, you're our biggest trading partner: We know perfectly well  that if you go down the plug-hole, we're going with you. We have every reason to wish you well.

 I won't go into the reasons why I think your recent Iraqi adventures have been - taking the long view - an ill-advised  tactical error. By the time you read this, Baghdad may or may not look like the craters of the Moon, and many more sheep  entrails will have been examined. Let's talk, then, not about what you're doing to other people, but about what you're  doing to yourselves.

 You're gutting the Constitution. Already your home can be entered without your knowledge or permission, you can be  snatched away and incarcerated without cause, your mail can be spied on, your private records searched. Why isn't this a  recipe for widespread business theft, political intimidation, and fraud? I know you've been told all this is for your own  safety and protection, but think about it for a minute. Anyway, when did you get so scared? You didn't used to be easily  frightened.

 You're running up a record level of debt. Keep spending at this rate and pretty soon you won't be able to afford any big  military adventures. Either that or you'll go the way of the USSR: lots of tanks, but no air conditioning. That will make  folks very cross. They'll be even crosser when they can't take a shower because your short-sighted bulldozing of  environmental protections has dirtied most of the water and dried up the rest. Then things will get hot and dirty indeed.

 You're torching the American economy. How soon before the answer to that will be, not to produce anything yourselves,  but to grab stuff other people produce, at gunboat-diplomacy prices? Is the world going to consist of a few megarich King  Midases, with the rest being serfs, both inside and outside your country? Will the biggest business sector in the United  States be the prison system? Let's hope not.

 If you proceed much further down the slippery slope, people around the world will stop admiring the good things about  you. They'll decide that your city upon the hill is a slum and your democracy is a sham, and therefore you have no  business trying to impose your sullied vision on them. They'll think you've abandoned the rule of law. They'll think you've  fouled your own nest.

 The British used to have a myth about King Arthur. He wasn't dead, but sleeping in a cave, it was said; in the country's  hour of greatest peril, he would return. You, too, have great spirits of the past you may call upon: men and women of  courage, of conscience, of prescience. Summon them now, to stand with you, to inspire you, to defend the best in you.   You need them.

 *Margaret Atwood studied American literature - among other things - at Radcliffe and Harvard in the 1960s. She is the  author of 10 novels. Her 11th, "Oryx and Crake," will be published in May. This essay appeared originally in The Globe and  Mail (Toronto), March 28, 2003.