Washington ? Secretary of State John Kerry’s cardinal rule in trying to restart the Israeli-Palestinian peace process has been that he won’t talk publicly about the details, so it’s difficult to know how he’s doing. But he’s still hard at it, and he seems to be employing some modest variations on the traditional choreography of Middle East shuttle diplomacy.

Kerry has made a restart of the peace process a personal priority: He has played his cards close to the vest during a string of private meetings with key Israeli and Arab officials. But it appears that he’s seeking agreement on basic parameters — the borders for a Palestinian state and an understanding about Israel’s security requirements — that would allow negotiations to begin in earnest.

“What we want to do is to restart the peace talks with the Palestinians,” Israeli Prime Minister Benjamin Netanyahu told Kerry in the presence of reporters last Thursday. But Netanyahu wants a clear U.S. commitment that any Palestinian state will be demilitarized and won’t become a base for launching attacks on Israel. 

Kerry knows all the reasons why this new peace effort could fail. Yet he’s back in the region this week on his fourth visit in the last two months, and diplomatic observers say he’s surprisingly close to getting the parties back to the table.

How has Kerry addressed the challenge that has defied so many of his predecessors? He and his staff won’t discuss tactics, but you can sense some of his starting points: Rather than waste time haggling over a formal settlement freeze or other confidence-building measures, he got both sides to make unannounced concessions. The Israelis have refrained from making inflammatory announcements about new settlements, and the Palestinians have held back from taking their cause to the United Nations.

Kerry’s window of opportunity will close soon: If he can’t produce real negotiations by this summer, the Palestinians will be back at the U.N. in September, and the Israeli settlement machine will be an issue again.

Kerry has taken some innovative steps to sweeten a negotiating option that has been soured by so many decades of failure. In effect, he has front-loaded some potential benefits, so that Israelis and Palestinians can see what could be gained if they negotiated the difficult final-status issues.

The first of these steps was to reanimate the Arab Peace Initiative, originally launched in 2002 by Saudi Arabia and repackaged this year by Qatar, which is always looking for a way to show up its big brother in the Gulf.

The revived initiative, ratified by Arab League foreign ministers in April, included several important amendments. The Arabs called for a Palestinian state within the 1967 borders, as before, but endorsed a “comparable and mutually agreed minor swap of the land,” in the words of Sheik Hamad bin Jasim al-Thani, Qatar’s peripatetic foreign minister. Second, and perhaps more important, the Arabs said that if the deal were ratified by both sides, “they would consider the conflict ended,” as Kerry put it, and they would have peace treaties and normalized relations with Israel.

The bottom line for Israel is that rather than just a two-state solution, it would get a 22-state solution (the Arab League members) and even a 57-state solution (if you add in the additional Muslim countries in the Organization of Islamic Cooperation).

Netanyahu offered only a grudging acknowledgement of the rejiggered Arab Peace Initiative in April. But Israeli President Shimon Peres made an unusual intervention, specifying that such a two-state solution “is also accepted by us and a broad structure of support is being created for making progress.” The Peres statement appears to be the operative Israeli position.

Kerry’s second sweetener has been a $4 billion economic assistance plan for the West Bank and Gaza. It was crafted with help from Israeli and Palestinian business executives working with the international group of nations known as the Quartet, and was discussed by Kerry last weekend at the World Economic Forum meeting in Jordan.

“He wants to convey to people in the region how peace would improve their daily lives,” explained one Kerry adviser. The economic package is not meant as a substitute for a final-status agreement, as Palestinians fear, but to “underscore the desirability of peace.”

Kerry has one unlikely advantage in the frustrating, obstacle-strewn search for an Israeli-Palestinian peace. He knows what it’s like to fail at something big in life in his unsuccessful 2004 Democratic presidential campaign — and to stay in the arena for one more try at achieving greatness.