Five days before the 20th anniversary of the United States' withdrawal from Vietnam, former U.S. secretary of defense Robert S. McNamara told an overflow crowd at the Institute of Politics last night that he was "wrong, terribly wrong" in prolonging the Vietnam War.

His recent book In Retrospect: The Tragedy and Lessons of Vietnam has garnered enormous publicity nationwide in the last two weeks.

"I think tonight we as Americans should recognize that hundreds of thousands of Americans suffered," McNamara said. "The question is, what should we do today?...Try to find out how it came about."

Three other panelists spoke on McNamara's book in a discussion moderated by Director for Science and International Affairs Graham T. Allison Jr. '62: Warren Professor of American History Ernest R. May, Young Professorof Sino-Vietnamese History Hue-Tam Ho Tai andDirector of Indochina Programs at the HarvardInstitute for International Development Thomas J.Vallely.

Save two emotional outbreaks, the crowd of 800sat quietly as McNamara posed and answered fourquestions about his involvement in the conflict.

But the audience fully applauded McNamara onlyonce, when he said, in reference to his fourthquestion about the lessons that Vietnam taught,that leaders are not omniscient.

"We don't have the God-given right to shapeevery nation to our own interests," McNamara said."But we're still trying to do it, and that's sad."

There was no applause for the former secretary,however, when two speakers in the question andanswer period--one a Vietnam veteran, one thewidow of a slain pilot--asked him why he allowedthe war to continue.

"I'm sorry, sir, but your book and yourpresence are obscenities," said one Vietnamveteran in the audience.

"At some time, sir, your opinion on this warchanged," the man continued in a steady but angryvoice. "Why did McNally [a man in his battalion]die when you knew this war was a mistake? Why didyou remain silent?"

When McNamara responded the veteran should readthe book to find that out, he cried, "Sir!"McNamara replied, "Wait a minute! Shut up!"

"What we were trying to do was use militarypressure to move the North Vietnamese tonegotiations," he continued. Some in theadministration, he said, felt losing Vietnam wouldmean a catastrophe for the western world, perhapsWorld War III. McNamara said he now believes theywere wrong.

An anonymous voice broke through McNamara's,however, shouting, "You should have dropped thebomb, Bobby! You know that...You should haveresigned. You know that as well as I do." The manwas silent after two outbursts.

A second emotional moment came when a Vietnamwidow described a meeting in 1968 which McNamaraand other high-ranking official attended. They metfor less than an hour about a pilot shot down overa Vietnam island, she said, and McNamara laterwrote in a secret document that there should be norescue.

"I'm that guy's wife and you said on page six[of the document that] no rescue attempt should beneeded," the woman said. "All those years I wantedone of those 10 people [at the meeting] to say tome, 'I am sorry.' Will you say it: 'I am sorry'?"

McNamara said he did not recall the meeting andasked to see the document. The woman handed it tohim. Her son, who was also in the audience, thengave McNamara a letter.