Holocaust survivor Elie Wiesel, a Nobel Peace Prize Laureate, expressed his support for the United State’s war on terrorism at his speech Sunday afternoon.

“We have the right to intervene because every human being is worthy of our solidarity,” he said.

In his first visit to Northwestern in 25 years — though many students attended a Chicago speech by Wiesel last October — the author and activist addressed the dangers of fanaticism.

Saddam Hussein, he said, was a fanatic who needed to be removed from power.

“How could we have allowed him to remain?” he asked. “The fact is, we had to go in. Would I have said the same thing if I knew there were no weapons of mass destruction? I don’t know.”

A capacity crowd of 1,000 at Cahn Auditorium welcomed Wiesel, 75, with a standing ovation. The author, a revered human rights advocate and professor at Boston University, has received international acclaim for his Holocaust memoir “Night.” The book describes his experiences during his two years in concentration camps during World War II, where his parents and younger sister died.

Wiesel’s speech, co-sponsored by the Dawn Schuman Institute and the Fielder Hillel Center, sold out within a week after tickets were made available a month ago. About 120 signed copies of Wiesel’s new book, “Wise Men and Their Tales,” on sale outside the auditorium also quickly sold out.

The author often spoke softly and simply, echoing his writing style. Seated in front of a table on the stage, he leaned forward slightly toward the microphone, carefully choosing his words.

“(Terrorism) has made the world into a battlefield,” he said in a slight German accent. “Today every country is affected. The whole world is at war. We never know when, where or how the next terrorists will strike.”

Though other ideologies such as communism may have subsided, fanaticism is “a growing phenomenon,” Wiesel said.

He warned that fanaticism in power is dangerous because it denies humans their “right to doubt” and to question their leaders.

“(The fanatic) believes whatever he says is the ultimate truth,” he said. “That is madness.”

Wiesel also addressed the Malaysian prime minister’s remarks at a conference that, “the Jews rule this world by proxy. They get others to fight and die for them.”

“What makes it worse is when he made this speech, he got a standing ovation,” Wiesel asked. “Fifty-six of his peers stood up and applauded him for his stupidity and for his hatred and, therefore, for his fanaticism.”

A murmur arose when Wiesel mentioned Holocaust revisionism. The last time he was at NU, he said, was to address a “Holocaust denier.”

“Why do they put so much passion into their work as we do now?” he asked. “They want to rouse more hatred to the Jews. Because if what they say is true — that we invented our suffering — then why shouldn’t we be hated?”

Although Wiesel never mentioned by name NU Prof. Arthur Butz, a Holocaust revisionist, many audience members inferred the reference. Butz wrote “The Hoax of the Twentieth Century,” a Holocaust revisionist book, in 1976.

Rabbi Dov Hillel Klein, Tannenbaum Chabad House director, said he was “disturbed” that Wiesel seemed “somewhat pessimistic,” but still thought the speaker presented a message of hope.

Wiesel’s presence strongly affected many audience members, including Weinberg sophomore Pooja Chitneni.

“He and Nelson Mandela are my two favorite people in the world,” she said. “They’ve gone through so much and they didn’t let it ruin their view of the world. They’re still optimistic and hopeful.”