It may seem hard to believe, given America's vital regional interests, but the last president to develop a deal to mitigate Middle Eastern violence - and throw the full weight of his presidency and the international community behind it - was Dwight D. Eisenhower, in 1957. John F. Kennedy had no wars to respond to, and was largely concerned with preventing Israel from acquiring nuclear weapons. But ever since Johnson - since the Six-Day War, that is - one president after another has behaved as though America's role was limited to facilitating a negotiation between Israelis and their neighbors: a kind of regional Dr. Phil. Israel was the client state, yet presidents, in effect, worked to preserve its freedom of action. They might carp half-heartedly about settlements, or empower their secretaries of state to exert economic pressure about particular instances of foot-dragging (Kissinger on Rabin in 1975, or Baker on Shamir in 1991). But presidents did not - how did Colin Powell put it? - presume to want peace "more than the parties themselves."

Some have argued, notoriously, that the Israel lobby must be credited (well, blamed), if presidents have been relucant to lead. This view is too elegant for competent historians, and it also fails to explain why things are changing so fast in Washington. With Benjamin Netanyahu sitting edgily at his side this week, Barack Obama sternly included Americans and Europeans as interested parties in the regional goings-on, too. And he seems poised to sketch out a plan that will bear his stamp, beginning with his upcoming speech in Cairo. Obviously, he wants Israelis to imagine joining a bigger peace process than any they could themselves organize or scuttle. Why Obama and not his predecessors?

This is not the place to review the records of eight previous administrations. But there is an obvious taxonomy for presidents, at least with respect to this region, and Obama emerges as one of a kind. First, we might categorize presidents according to their knowledge of the region - if not their subtlety about the Arab world, then their sophistication about the developing world more generally. This may be compared with, say, a president spouting a Manichaean ideology in which preemption of dark forces takes precedence over any peace, which could anyway never be trusted. (The latter view was hammered into a platform by early neoconservatives during the late 1970s, one that cast America in a perpetual fight against evil - "evil empire," "radical evil," "axis of evil" - and cast Israel as America's biggest aircraft carrier.)

Second, we might categorize presidents as relatively strong or weak. Do they enjoy broad popularity and reliable congressional support for their agenda, however modest, or does presidential popularity fluctuate with media-hyped judgments of their efficacy or ineffectuality, or their virtues or peccadilloes, while each congressional action hinges on tough votes? Finally, do presidents have a peculiar soft spot for Israel, a penchant for seeing it as a tribute to freedom or the answer to an ingenuous religious impulse - as natural to the Middle East as the Holocaust museum is to the Washington Mall or "Jerusalem" is to Baptist hymns? Or, do presidents see Zionism admiringly enough, but mainly through the prism of the practical security problems Israeli leaders say they have?

When you think about it, Obama is the only president since Eisenhower whose profile resembles that of Eisenhower - which means virtually complete freedom to act. One, he has worldly sophistication and knows it; he was brought up in Jakarta and is not put off by the extremist language of the poor and desperate and young; yet his allergy to ultra-nationalist rhetoric was hard won, when he rejected (as only a "mutt" could) Louis Farrakhan's acolytes in Chicago. Two, he has an unprecedented mandate at home. He also enjoys the European Union's support. But, he also has something Ike did not have, the affections of the vast majority of American Jews, 78 percent of whom voted for him. Against this trifecta, it will be hard to flog Israel's role in a clash of civilizations.

Netanyahu - as indeed many Israelis of a certain age - may say that what makes Obama unique is his inexperience, or recklessness, or both. That his presidential predecessors learned from Eisenhower's failure not to meddle in Israeli security strategy. After all, Eisenhower and secretary of state John Foster Dulles forced the Israeli government to evacuate the Sinai after the Suez War. In return, Israel got the opening of the Straits of Tiran, but manned by UN peacekeepers - "the umbrella," as Abba Eban memorably complained to the UN Security Council after the 1967 war, that was taken away "as soon as it begins to rain." Indeed, the justifications for making the Sinai's occupation permanent in 1957 were the same as the ones advanced after 1967: keeping Palestinian terrorism in check, strategic depth through territorial expansion, "deterrence."

But Obama surely knows that this is a very partial assessment of Eisenhower's achievement. Just as the current occupation makes a succession of intifadas inevvitable, continued occupation of the Sinai after 1957 would hardly have made a new war with Egypt less likely. As Israelis learned bitterly in 1973, occupation made war inevitable, and on terms that made a preemptive strike diplomatically impossible. For his part, Eisenhower proved that when the U.S. and Europe act together, and rally the UN and America's regional clients, deals get done. On the whole, the decade after Dulles' ultimatum proved to be the golden age of state building, Hebrew cultural innovation and immigrant absorption. So the question is not really why Obama is trying this, but, what took so long?

Bernard Avishai is the author, most recently, of "The Hebrew Republic" (Harcourt). He blogs at www.bernardavishai.com.