In 1986, Mr. Cohen was the catalyst for the first three clandestine sessions in Paris and Brussels between Israeli and Palestinian representatives, two from each side.
Ostensibly, those talks were limited in scope to missing or captured soldiers, but they went beyond those matters. The talks stalled when the P.L.O. refused to budge on its demand that the Soviet Union join on an equal footing with the United States in an international mediation conference, and they collapsed a few months later after Shimon Peres departed as prime minister.
“Steve was the initiator of these meetings and served as the go-between,” Shlomo Gazit, one of the two Israelis and a former head of the military intelligence service, said in an email on Thursday. “The fact that Steve was Jewish did not in any way disturb the parties. Steve did not give up, and for years did his best to renew meetings and talks, unfortunately without success.”
Ephraim Sneh, an Israeli politician and former deputy defense minister, described Mr. Cohen in an email as “the lone guerrilla warrior of peace.”
Despite repeated setbacks, Mr. Cohen’s broad recipe for peace in the troubled region remained remarkably consistent, according to “The Go-Between,” a memoir he published last year (written with Oren Rawls), as well as other accounts.
He generally favored the gradual emergence of a United Nations-mandated Palestinian state supervised by the United States and the North Atlantic Treaty Organization, though that, he wrote, would require “the gamble for peace by a great regional leader” and “the American refusal to take no for an answer.”
In an interview with the Times columnist Thomas L. Friedman in 2003, Mr. Cohen said: “Israel can’t force the Palestinians to be reasonable, to pursue their interests and not their passions, but it can create a context where they are more likely to do so than not. But with its relentless settlement activity, and responding to every Hamas provocation by smashing the Palestinian Authority, Israel has not done that.”
Meanwhile, Mr. Cohen said in 2002, “it turns out Arafat wanted two Palestinian states.”
“He wanted a Palestinian state for the West Bank and Gaza to be negotiated with Israel today,” he added. “And he wanted a Palestinian state inside Israel that would be brought about by a return of Palestinian refugees and their soaring birthrate tomorrow. Israel was ready to give him one Palestinian state, but not two. And Arafat didn’t have the courage to tell his people that.”
Stephen Philip Cohen was born in Quebec on May 28, 1945. His father, Harry, an immigrant from Lithuania, owned an auto parts business. His mother, born in Montreal to Jewish immigrants from Romania, was a bookkeeper.
He received a bachelor’s degree from McGill University in Montreal and a doctorate from Harvard. He was an assistant professor at Harvard, an associate professor at the City University Graduate Center and an analyst for the Israel Policy Forum, a Manhattan think tank that favors a two-state solution.
In 1973, after Egypt launched a surprise attack against Israel in what became known as the Yom Kippur War, Mr. Cohen took a leave from Harvard to enlist in the Israeli Army and use his training as a social psychologist to bolster morale at the front.
In addition to his wife, the former Elaine Rachel Shizgal, he is survived by three daughters, Rabbi Tamara Ruth Cohen, Rabbi Ayelet Sonya Cohen and Maya Orli Cohen; five grandchildren; and a brother, Prof. Richard I. Cohen of the Hebrew University of Jerusalem.
While Mr. Cohen was sometimes confused with other academics of the same name (Stephen F. Cohen, a Russia expert at New York University, was once bear-hugged at a party by President Bill Clinton, who wanted to consult about Middle East policy), he carved out a reputation as a go-to wise man on all matters Middle East.
After the attacks on Sept. 11, 2001, he paraphrased Lincoln in reacting to anger at Muslims, cautioning that “we must fight those among them who pray only to the God of Hate, but we do not want to go to war with Islam, with all the millions of Muslims who pray to the same God we do.”
He also expressed concern that some of the outpouring of support in Europe for Palestinians had a more sinister motivation.
“For too many Europeans, Arabs are of no moral interest in and of themselves,” he said in 2003. “They only become of interest if they are fighting Jews or being manhandled by Jews. Then their liberation becomes paramount, because calling for it is a way to stick it to the Jews.”
For all the successes he achieved through his diplomatic and psychological skills, Mr. Cohen had no illusions about the so-called peace process.
“The Israelis wanted peace, while maintaining underlying control of the Palestinians,” he said in 2000. “The Palestinians wanted peace, without giving up their hatred of Israel. With such ambivalence we can only get cease-fires.”
But he did not consider his quest quixotic. In 1986, he conferred with Mr. Arafat (whom he had first met in 1981) in a desert bunker just four months after the Israelis had demolished his headquarters in Tunis, yet the P.L.O. leader still agreed to send negotiators to Paris.
“Three decades later,” he wrote in an essay published this week in The Forward, “it is hard to imagine a future between Israelis and Palestinians free of burning confrontation. Yet it is worth recalling that hope for peace was no greater in 1986 than it is today.
“Eventually, inevitably,” he continued, “the Israeli and Palestinian leaders will conclude” that “finding a way of living under better circumstances is the only realistic goal.”