I suspect that being out of sync reflects a deeper reality. The costs of making peace have always been perceived as high, and it takes great courage or profound pressure for Middle Eastern leaders to make the leap. It takes little to dissuade them from doing so. If there are leaders who see themselves in historic terms-as Anwar Sadat and Menachem Begin did-the fact that one will take the leap is bound to leave the other feeling that he must also meet the challenge. More often there have been asymmetries in leaders: Rabin and Asad seemed alike in many respects. Both were cautious, prone to calculate carefully, disinclined to move in any but small steps, and highly suspicious. But Rabin, having been voted in as Prime Minister a second time, was poised for historic choices. Asad could not break the habit of a lifetime, finding it impossible not to haggle over every issue when Rabin was expecting boldness to be matched by boldness. Peres, by inclination, was a leader always looking for revolutionary, not evolutionary, moves. It was no surprise that Asad would not embrace the Peres approach, even if the Rabin assassination made him a more flexible negotiator. Later Asad, seeing succession as the overriding imperative, was ready to change his behavior for a short period during Barak's tenure. But peace was a derivative of the succession issue, and if he thought the pursuit of it would jeopardize his son's chances of succeeding him, he was bound to change directions.

And that is an essential point. Events have consistently undone opportunities. Violence has often reduced the ability and the willingness to make possible concessionsfor peace, and at times undercut those perceived as too accommodating. Four suicide bombings in nine days in 1996 changed the climate in Israel and elected Bibi Netanyahu. Without the suicide bombings in 1996, Peres (wearing the slain Rabin's mantle) would have won with an unprecedented mandate. Peres was already a man on a peace mission, and given the progress made at Wye, a deal with Asad probably would have been produced within a year or so. An Israeli-Syrian deal would have fundamentally altered the region. There would have been no Hizbollah model indicating that violence works. There would have been no base in Syria or Lebanon for militant rejectionists. There would have been pressure on Arafat to do a deal, not avoid one.

Why is the peace process so quick to come undone? One cannot ascribe this only to a lack of courageous leaders. Something more fundamental is at work here. As a rule, Arab leaders lack legitimacy. There is no sense of participation-politically or economically-among most Arab publics, and Arab leaders have traditionally been selected, not elected-or worse, they have seized power. So they are easily put on the defensive and fear being accused of conceding principles or perceived rights. Their sense of vulnerability makes them risk-averse, and events that heighten their perception of risks band to dissuade them from persevering.

Democratically elected Israeli leaders don't lack legitimacy. But they preside in a highly competitive political environment, with governments that are always based on coalitions of different parties. Their rivals can exploit acts of violence and terror, particularly because most Israelis continue to question whether the Arabs or the Palestinians are truly prepared to live with them. The inherent distrust of their neighbors' intentions makes it difficult for Israeli leaders to persevere in peacemaking in circumstances in which acts of terror take place. In such an environment, extremists on both sides have the capacity to undo moments of great promise.

For all that, peacemaking efforts have not died, even when moments of opportunity have been lost. That too reflects an important reality: There is an underlying desire for peace among both publics. There is an understanding among the mainstreams in the Arab world and in Israel that continuing conflict is ultimately not an acceptable alternative. But both sides will have to adjust their attitudes and behaviors if they are to make peace a reality. Here, too, lessons from the past provide a clear guide as to where each must change.