I've been a Palestinian firster for most of my professional life. I believe that the Palestinian issue is the core of the Arab-Israeli conflict, the key to regional peace, and the sine qua non for preserving Israel as a Jewish democratic state. These arguments remain valid. What's changed is that a conflict-ending agreement between Israelis and Palestinians may no longer be possible. I choose my words carefully here. Varying kinds of accommodations cease fires, informal cooperation and temporary arrangements may still be possible. But an agreement now or perhaps for the foreseeable future that revolves conclusively the four core issues (borders, Jerusalem, refugees and security) isn't. Three realities drive my pessimism and should force experts, politicians and would be mediators to keep their enthusiasm for quick or easy solutions under control. First, there are the issues. There is a myth out there driven by the Clinton parameters of December 2000, the Taba talks in 2001, the Geneva accord a year later, and the hundreds of hours of post Annapolis talks between Israelis and Palestinians that the two sides are "this close" (thumb and index finger a sixteenth of an inch apart) to an agreement. The gaps have now narrowed, perhaps impressively, but closing them, particularly on the identity issues such as Jerusalem and refugees, is still beyond the reach of negotiators and leaders. It's not that there are metaphysical or magical reasons why these core issues can't be resolved; it's that the political will is lacking among leaders to reach an agreement and that the current situation on the ground between Israelis and Palestinians makes it impossible for them to do to. That everyone knows what the ultimate solution will look like (an intriguing notion that is supposed to make people feel better) is irrelevant if the circumstances for an agreement don't exist. THIS BRINGS me to my second point. The dysfunction and confusion in Palestine make a conflict-ending agreement almost impossible. The divisions between Hamas (itself divided) and Fatah (even more divided) are now geographic, political and hard to bridge. Until the Palestinian national movement finds a way to impose a monopoly over the forces of violence in Palestinian society, it cannot move to statehood. The hallmark of any state's credibility (from Sweden, to Egypt, to Poland) is its control over all the guns. Criminal activity is one thing; allowing political groups to challenge the state, or its neighbors, with violence is quite another. What Palestinian leader can claim to speak for all Palestinians or negotiate an agreement against the backdrop of a separate entity which controls 1.3 million Palestinians, possesses a different view of governance and nation-building and often attacks its neighbor? And what Israeli prime minister could ever make concessions to a Palestinian leader who doesn't control all of the guns? There is no solution to this problem now. Only by restoring unity to the Palestinian house will a conflict-ending agreement be possible. And that agreement will have to take into account the needs of both Israel and a unified Fatah-Hamas negotiating position which doesn't reflect Hamas's extreme views and irredentism. Third, there is serious dysfunction at the political level in Israel as well. Israel has its own leadership crisis. The state is in transition from a generation of founding leaders with moral authority, historic legitimacy and competency to a younger generation of middle age pols who have not quite measured up to their predecessors or to the challenges their nation faces. The leadership deficit is a global phenomenon, but not all states are sitting in a dangerous neighborhood on top of a political volcano. Is there an Israeli leader today who has the authority and skill to make and sell the tough choices required for Israeli-Palestinian peace? So what to do? My days of giving advice to Israelis and Palestinians are over. I would, however, respectfully suggest to President-elect Barck Obama, in my capacity as an American who doesn't want to see America fail again, that he recognize there's no deal in this negotiation now. Manage it as best you can: help support an Israeli-Hamas ceasefire, train PA security forces, pour economic aid into the West Bank and Gaza, even nurture Israeli-Palestinian negotiations on the big issues, but don't think you can solve it; you can't. Instead, go all-out for an Israeli-Syrian agreement which is doable and will enhance American credibility to confront Hamas, Hizbullah and Iran over time with tough choices, and improve America's regional standing. Then, perhaps, your chances on the Israeli-Palestinian track may be better. In the interim, I'm afraid sadly that the bottom line for Israelis and Palestinians is not a good one: Israelis will have their state, but Palestinians will never let them completely enjoy it. The writer, a public policy scholar at the Woodrow Wilson International Center for Scholars, worked as an advisor on the Middle East for six Democratic and Republican secretaries of State. He is the author of The Much Too Promised Land: America's Elusive search for Arab-Israeli Peace.