On an April evening in 1981, Ngo Vinh Long left a Harvard University panel discussion about Vietnam, his home country. He was an outspoken opponent of the Vietnam War, and Harvard security police escorted him outside because threats had been made on his life.
Just before they reached his car, a man stepped from behind a tree along Oxford Street in Cambridge and hurled a Molotov cocktail. It burst and splintered against the car windshield without exploding, though the officers were splashed with gasoline and sprayed with glass fragments.
The first Vietnamese student to attend Harvard, Dr. Long had always spoken frankly about his home country and had declined to denounce its government in the years after US forces departed at the end of the Vietnam War. His stance angered many Vietnamese refugees in the United States, including the man who threw the gasoline bomb that evening.
“They accuse me of being a Communist agent. I am not,” Dr. Long told the Globe days after the attack. “I sympathize with many things in Vietnam today and am critical of others. I am an independent scholar.”
Arriving in the United States in the early 1960s, initially as a high school foreign exchange student, Dr. Long became a vocal opponent of the Vietnam War while attending Harvard.
“The present policy in Vietnam is not only disastrous to the US, but is destroying Vietnam,” he told a crowd of about 600 at Sanders Theatre at Harvard in February 1968, a couple of weeks after North Vietnamese forces launched the Tet Offensive, which resulted in thousands of deaths among civilians and US and South Vietnamese troops.
In May 1972, Dr. Long was among the speakers on a Boston Common stage during activities to mark the nationwide Moratorium to End the War in Vietnam.
Christian G. Appy, a history professor at the University of Massachusetts in Amherst, included Dr. Long’s recollections in the oral history “Patriots: The Vietnam War Remembered from All Sides.”
“He spoke and wrote against the war at a time when few Vietnamese even lived in the United States,” Appy wrote to introduce Dr. Long’s section, in which he detailed his life in Vietnam and what led him to oppose the war.
Born on April 10, 1944, in Vinh Long Province in Vietnam, Dr. Long was one of several siblings and was a boy during the war between French and Vietnamese forces in the late 1940s and early 1950s.
French patrols “killed a lot of Vietnamese,” he recalled in the oral history, and “dumped the bodies into the river and the currents carried them into lakes and ponds.”
While Dr. Long was growing up along the Mekong River, he recalled in a 1982 Globe interview, “I would swim with floating corpses. These were people executed by the French. Sometimes I would get so sick, I’d be sick for a week.”
Angered by what he saw, Dr. Long refused to learn French, which he called the language of “these barbarians.”
He told the Globe that his father, Ngo Ngoc Tung, suggested he learn English instead. Dr. Long’s father and mother, Ho Thi Ngoc Vien, were activists.
Traveling to what was then Saigon, and is now Ho Chi Minh City, Dr. Long and his father found a copy of “Great Expectations” by Charles Dickens, along with a dictionary that lacked a pronunciation guide. The two went through the novel, guessing at how to say words aloud.
Those rudimentary English lessons left him fluent enough to be hired in the early 1960s, as a teenager, to work as a translator when US personnel began arriving in Vietnam. The US Army trained him to make military maps and sent him into the countryside.
“He would tell me about riding elephants while doing that, because he was traveling in places with no roads,” said his wife, Mai Huong Nguyen of Bangor.
But what Dr. Long saw in the hamlets he visited turned him against the Vietnam War and the US involvement.
“In some places, people were dying of hunger in droves,” he said in the 1982 interview. “I stayed in one village for two months, and each month about 200 people died of hunger.”
Though his initial interest in moving to the United States was souring, a friend who worked for a US agency persuaded him to go, anyway, to further his education.
“I felt maybe if I could make it to the states,” Dr. Long recalled, “I could tell what was happening in Vietnam.”
He told the Globe that he spent a year as an American Friends Service Committee high school exchange student in Joplin, Mo., often giving speeches to service organizations.
Then he went to Harvard, where he participated in antiwar teach-ins. He later led a Vietnam resource center in Cambridge, edited a newsletter, and began writing books while graduating from Harvard with a bachelor’s degree and a doctorate.
His first marriage to Nguyen Hoi-Chan, who had been a Radcliffe College student, ended in divorce. They had a son, Ngo Vinh-Hoi, who now lives in Brooklyn, N.Y., and a daughter, Ngo Thai-An, of Oakland.
The University of Maine hired Dr. Long in 1985, and he has been on the faculty ever since. The Adelaide and Alan Bird professor of history, he wrote on his webpage that he has taught courses focusing on “East Asia, South Asia, Southeast Asia and the relations of the countries in these regions with each other and with the United States.”
In 1998, Dr. Long married Mai Huong Nguyen, a clinical social worker and mental health counselor.
“He was extremely generous with a lot of people with his time, and if he could help people out,” she said, adding that her husband “was very humorous. He punned a lot and we would laugh at how corny his puns were.”
In addition to his wife and his children from his first marriage, Dr. Long’s survivors include two sons from his second marriage, Ngo Vinh-Thien and Ngo Vinh-Nhan, both of Bangor, and two grandchildren.
The family planned to hold a private memorial gathering.
In May 1982, a year after the Molotov cocktail attack, a jury found the man who police had arrested not guilty of several charges by reason of insanity, after psychiatrists testified that he suffered from post-traumatic stress disorder.
The man was a Vietnamese veteran of the Vietnam War who, according to testimony, had seen his best friend tortured and executed when they were in a Vietnam prisoner of war camp.
Threats of violence against Dr. Long by others continued in those years, however. He told the Globe that people broke into his home to steal his research materials, typewriter, and camera.
“There are very few people in the world doing research on Vietnam. I think I should talk about it,” he told the Globe in 1982.
“As a scholar,” he added, “my duty toward Vietnam and the United States is to point out the realities of Vietnam — what’s right, what’s wrong, what the problems are.”
Bryan Marquard can be reached at email@example.com.