Former Secretary of Defense William J. Perry advocated moving toward a world without nuclear weapons during a speech at the Institute of Politics yesterday.

According to Perry, who is now a professor at Stanford University, the next challenge for achieving this goal is the ratification of a worldwide nuclear disarmament treaty.

The United States should not accept that nuclear terrorism or war is inevitable, he said.

“Our problems are man-made, and therefore they can be solved by man,” said Perry, who served under President Clinton.

Perry supplemented his lecture with clips from “Nuclear Tipping Point,” a documentary he co-produced with former Secretary of State Henry A. Kissinger ’50 and two others. The clips showed the development of nuclear weaponry throughout history, beginning in President Kennedy’s administration and ending in President Obama’s 2009 nuclear disarmament speech from Prague, which Perry called a “miracle.”

During the question and answer session preceding the lecture, Perry addressed the precarious nature of some countries in possession of nuclear weapons, such as Pakistan—a nation that refuses to sign a nuclear non-proliferation treaty until India does so first.

“Right now, Pakistan is number one on a list of nuclear nightmares,” Perry said.

The speech, entitled “Have We Reached the Nuclear Tipping Point?”, was the second Robert S. McNamara Lecture on War and Peace. Former Georgia Senator Samuel A. Nunn gave the inaugural lecture in 2008 at the Institute of Politics, where he said a nuclear-free world is possible.

The lecture series is named after the defense secretary of Presidents John F. Kennedy ’40 and Lyndon B. Johnson. Perry said McNamara served as an inspiration to him and warned him to avoid similar mistakes as defense secretary.

Graham T. Allison Jr. ’62, the director of the Belfer Center for Science and International Affairs, moderated the forum.

Perry concluded his speech by stressing the urgency of creating a nuclear-free world.

“I believe that time is not on our side,” Perry said.

—Staff writer Melanie A. Guzman can be reached at melanieguzman@college.harvard.edu.