THE LETTER WAS TUCKED away on a corner of the editorial page, but the headline drew my attention, and when I read it I could hardly believe my eyes. On a visit to Washington, said the writer, he had gone with some friends to Arlington Cemetery. "I was shocked to discover," he continued, "that the graves of our military heroes are being mowed with Japanese-built Ford tractors. This should not be tolerated."

I have been associated with America and Americans for most of the past two decades, first as a student, then as a journalist. I now call this country my home: I live here with my American husband and a young son. I feel comfortable here, and I have never been made to feel uneasy because I am Japanese -- until these last few months.

Every Japanese history student learns about American public hysteria in the '20s and '30s over what was then called the "yellow peril." Many more of us know about the passionate hatred of "the Japs" that swept the country after Pearl Harbor. But those things happened before I was born -- and until recently, to me they had always belonged to the history books.

When I first came to this country as an exchange student 18 years ago, a group of neighborhood kids made slant eyes at me and ran away, calling, "Hey, she's Japanese." That hurt my teen-age self-esteem, but I soon dismissed it as nothing more than childish cruelty. Most of the Americans I have met since then were kind-hearted, and showed me no hostility.

Even when people on Capitol Hill started referring to the possibility of a "trade war" earlier this year, I refused to believe they really meant it -- until I saw a quote attributed to a White House staffer in The Washington Post on April 7. In the wake of Tokyo's announcement of a 25 percent increase in its "voluntary" quotas on auto exports to the United States, the official had told a group of congressmen and business people, according to the article, that he thought, "The next time B52s fly over Tokyo, we better make sure they carry bombs."

I realized then that long-repressed resentment against the Japanese has been retained in the minds of some Americans -- and that it was suddenly resurfacing as frustrations over the snowballing trade deficit began to mount. The bombs-over-Tokyo remark, of course, also carried with it a resonance of the 40th anniversary of Japan's unconditional surrender in the wake of Hiroshima.

Still, I wanted to accept the common wisdom that what is said in Washington is often meant for political consumption in this city only. I wanted to believe that it didn't represent the feelings of people "out there" -- ordinary Americans in the rest of the country. But there I was wrong -- at least partially.

Recently I took on an assignment from a Japanese television network to help with a piece on the 40th anniversary of the end of the war. In the course of the reporting I discovered, to my great surprise, that there are still Americans who are bitter about my countrymen because of what happened 40 years ago.

The assignment required me to get in touch with American families whose fathers, husbands or sons were killed in the Pacific Theater.

Some were pilots shot down by Zeros; others were sailors who went down aboard ships sunk by Japanese torpedoes, gunfire or kamikaze suicide pilots. A number had been captured and perished in Japanese prison camps from exhaustion and starvation.

When I try to imagine the pain and sorrow those mothers and wives have lived with for 40 years, or how different the lives of their sons and daughters -- some of whom never met their fathers -- might have been if those men had returned alive, even badly wounded, I can almost understand their resentment against everything that is Japanese.

Nevertheless, it came as quite a shock when on several occasions as I tried to explain the television project on the phone, the person on the other end of the line hung up on me the instant I pronounced the word "Japanese." Even those who were willing to listen to me were, for the most part, reluctant to be interviewed.

When I asked one Gold Star wife whether her hesitation stemmed from the fact that I represented a Japanese network, she answered, "Frankly, yes," and added after a brief pause, "I know I shouldn't think this way." Then she broke into tears. She had lost her husband on a Japanese prison ship that hit a mine during its voyage from the Philippines to Japan.

Some of the families softened a bit after I explained that the aim of the program is to illustrate how much agony and suffering a war imposes on individuals and families no matter which side they are on. But for many others, the memories are still too painful to discuss with anybody, let alone with a Japanese, and in front of a camera to boot.

Because I love this country dearly, it pained me to discover that the passage of 40 years had done so little to heal the wounds inflicted upon its people by my country. The controversy over President Reagan's visit to a German cemetery in Bitburg made it clear that most Americans -- not only those of Jewish origin -- haven't forgiven the men who fought for Hitler. I dread to imagine the kind of emotion and antagonism that may be created if a president should decide to go to Yasukuni Shrine in Tokyo, which honors the war dead of Japan. The idea was raised at a few of the past presidential visits to Japan, but was rejected each time in view of the fact that even a Japanese prime minister cannot set his foot in the shrine without causing a public outcry, since there are so many Japanese who still think that a government official should not honor those who collaborated in the war effort.

I also realize that whatever hurt I feel is nothing compared to that of women and children whose loved ones never came back from the war. But it has made me wonder whether I haven't been overly optimistic right along in assuming that our two countries have formed an unbreakable bond of friendship across the Pacific.

No observer of the U.S.-Japan relationship today thinks that the ties are anywhere near as fragile as they were in the years that led up to Pearl Harbor. But it is disturbing to reflect on how quickly the post-World War I friendship between the two countries turned sour in the 1930s.

In "The Far Eastern Crisis," Henry Stimson's autobiographical study of the events that preceded the Pacific War, the former secretary of state writes at length about how he and then-Japanese ambassador to Washington Katsuji Debuchi agreed at a meeting in the fall of 1931 that the relationship between the two countries had had never been better. Forty-eight hours later, Stimson received news of the Japanese invasion of Manchuria, the event that he and many others believe was the first battle of the conflict that ended with Hiroshima and Nagasaki.

What worries me as much as the American expressions of irritation and hostility toward Japan, is a feeling of persecution and even paranoia that seems also to be developing in Japan, especially among younger people -- my generation -- who were born and educated after the war.

By the time these young Japanese reached the age of reason, the country was well on its way to becoming a world economic power. To them, nothing seems impossible or unattainable. They see Japan's economic success largely as a result of hard work and self-sacrifice by their fathers and by themselves. And they resent being blamed for the large U.S. trade deficit with Japan. In their eyes, it derives from America's mismanagement of its own economy -- including a very poor overseas marketing effort.

Their attitudes are a far cry from the feelings of the current generation of Japanese leaders, most of whom remember all too well the struggle and sacrifice it took to recover from the devastation the war left behind in Japan. At a particularly thorny moment of trade dispute a few years ago, Masumi Esaki, the chairman of the ruling Liberal Democratic Party's external trade forum, told me frankly that he thought Japan ought to accommodate American demands for opening of the Japanese market as a debt of honor, if nothing else. "We must not forget the generous help that the U.S. provided us during our difficult years after the war," he said, "Now it's our turn to help the U.S."

Soon -- in a decade or less -- the Esakis of Japan are going to be replaced by more self-confident, and sometimes more arrogant, young Japanese who have no memory of their country's obligations to America. I hope that their reaction to what they perceive as unreasonable U.S. pressure for trade concessions will not take the country on a dangerous course. But concerned Japan watchers may well remember a remark made a few years ago by a senior Japanese official to an American correspondent in Tokyo: "If you keep pressing too much, we can always switch sides."

Despite the danger, I am still optimistic about the future of the relationship between our two countries. Many of the families of men killed in the Pacific showed no reservations about discussing the war on Japanese television. In fact some veterans of the Battle of Leyte Gulf, one of the bitterest in the Pacific theater, went out of their way to help me with the project.

Even more encouraging is that for younger generations of Americans, Pearl Harbor is ancient history -- they see the Japanese as competitors, not as enemies. I was so relieved, and grateful, to hear Marine Col. William Bauer, commander of a test pilot squadron at Patuxent, whose father never returned from the air battle over Guadalcanal in 1942, say, "Hatred only destroys the person who carries it, not the target of his hatred." I hope this will be the spirit of America's relationship with Japan -- forever.