My life has been far more satisfying than I dreamed possible when I arrived in the United States, 38 years ago. I am privileged to head a world-class institution, the University of California, Berkeley. My former Ph.D. students are professors at major universities. My engineering research has contributed to America’s space technology, nuclear-reactor safety and energy technology.

Yet no matter the scope of my accomplishments, when many Americans see my face and hear my Chinese accent, they think of me as an immigrant, first and foremost. In the eyes of many, that has come to mean a drain on public services, a competitor for jobs and a threat to a cohesive society.

I have watched the campaign to discourage immigration with growing concern.Whether we preside over universities or work the fields, immigrants are becoming the scapegoats for America’s ills. I don’t object to controlling the volume of immigration. Today, with unprecedented shifts in the global population, no nation can afford to throw its borders wide open. But we are in danger of forgetting that America was built by immigrants, and that our immigrant heritage is the wellspring of our nation’s strength and vitality.

Even as a university chancellor, I am no stranger to the sharp sting of anti-immigrant hostility. Perhaps the most dramatic incident took place when I represented Berkeley a few years ago at a football rally after the Citrus Bowl. As I walked to the stage, a few people in the audience chanted, ““Buy American, Buy American.’’ This was profoundly disturbing. I am American and proud of it.

Just looking like an immigrant can make you the target of heckling. Any of us of Asian, Latin American and Middle Eastern heritage knows this. Several friends and family members have been subjected to taunts of ““Go back to your own country.’’ It’s difficult for them to respond; like Bruce Springsteen, they were born in the U.S.A. This anti-immigrant mood is not new. Throughout our history, whenever the economy suffered, immigrants became easy targets. But today it is not only the immigrants who suf-fer. Ultimately, all Americans stand to lose, native and foreign born alike.

Now our nation faces the formidable challenge of forging a unified society from highly diverse constituencies. The population is undergoing a rapid transformation, and by the middle of the 21st century, the majority of Americans will trace their roots to Latin America, Africa, Asia, the Middle East and the Pacific Islands.

Evolving into a cohesive society based on respect and understanding is far from automatic. Throughout human history, racial and ethnic tensions have divided and destroyed peoples and countries. The ethnic strife that ripped apart Brooklyn’s Crown Heights and South-Central Los Angeles is a sobering reminder of the challenge posed by rapid diversification.

Yet if there is a nation that promises to be a model for how to make diversity work, it is the United States. This is the nation with the strongest and deepest democratic roots. This is a nation with a living Constitution that guarantees rights to all its citizens. This is a nation that has taken pride not in its homogeneity, but in its immigrant heritage.

It was America’s promise that drew me here in 1956. Even as a penniless graduate student from China, I believed I could make a contribution in this land of opportunity. Indeed, I am deeply grateful to America for offering opportunities difficult to find anywhere else in the world.

Today, however, in the headlong rush to restrict immigration, we are jeopardizing this promise. Hundreds of state and federal measures have been introduced to curb legal and illegal immigration. The backers of these proposals often rely on inflammatory anti-immigrant rhetoric to rivet the attention of Americans, ignite their rage and move them to action.

In the hoopla, the debate is now moving away from the legitimate question of how much immigration America can sustain. Instead, we’re blaming immigrants for many of our most urgent problems and trying to convince ourselves that we’ll solve them by simply restricting immigration.

Effective immigration policy must be grounded in reason, not emotion. Racial and cultural hostilities fanned by the present anti-immigration frenzy must cool down. Then I am confident we can make immigration work for America, just as it has from the time of our nation’s infancy.

After all, in my 38 years here, I have seen this nation make amazing progress. When I came here to study in the South, I encountered Jim Crow segregation. Whites rode in the front of buses and blacks in the back. This racial system did not apply to Asian-Americans and left us in an ugly limbo. It troubled me and left a lifelong impression. The rest of the country was not free from racial discrimination. When I joined the Berkeley faculty, in 1959, my wife and I could not live in certain Bay Area neighborhoods.

In less than four decades, I have seen the enactment of civil-rights legislation that has created opportunities for all Americans. I have seen universities open doors to students who reflect our diverse society. I have seen women and men of all backgrounds become leaders in government, business, science, arts and education. Now I look forward to seeing the promise of America fulfilled. We can turn our national motto of e pluribus unum, or ““one out of many,’’ into more than an expression in a dead language. What it will take is the same kind of unwavering commitment that forged one nation from highly diverse colonies more than two centuries ago.

Immigrants are not the cause of America’s major problems. It’s time America stopped putting all the blame on immigrants and started facing up to the difficult reality of a world in transition. Let’s seize the opportunity to transform America into a model of diversity for the future.