When Daniel Ellsberg's son called him for help on a college essay about lessons of the Vietnam War, the legendary leaker of the Pentagon Papers figured he would be well-positioned to answer the question.

But nearly 30 years after Ellsberg let out the 7,000-page top secret account of U.S. involvement in Vietnam, he maintains that many of the war's most important teachings remain unlearned."I think we need to learn better lessons than we have learned yet," Ellsberg said. "I am very open and searching for new answers."

Ellsberg, speaking Monday at a conference on the "Legacy of 1968" at American University, said all those touched by the war have gleaned different lessons from it, and his own understanding of the events surrounding the nation's longest battle have evolved through the years. But the former State and Defense department official, now 70, says the Vietnam War clearly imprinted on him the importance of one American value: democracy.

"Democracy is needed and that's not what we have," says Ellsberg. "There are no guarantees . . . but our chances are better with democracy than without it."

Without true democracy and open understanding of foreign and military affairs, the United States will repeat the blunders that kept the nation in the Vietnam War even when the chances for success were gone, he said.

"I learned that my country is not an exception to the arrogance of power," Ellsberg said.

A retired researcher who is now an anti-nuclear activist, Ellsberg offered some of the other insights he arrived at about the Vietnam War. He challenged the idea that the battle ever had a "noble cause," saying it was an attempt to re-establish French colonialism.

In 1969, Ellsberg quietly photocopied the 47-volume history, which he saw as proof that American officials were lying about chances for victory in the war. The study had been ordered by Robert S. McNamara, defense secretary in the Kennedy and Johnson administrations. He leaked the papers to The New York Times in 1971.

Ellsberg was threatened with imprisonment, although charges were later dropped because of "government misconduct" under the Nixon administration. This included bugging Ellsberg's apartment, burglarizing his psychiatrist's office and attempting to bribe the judge.