The U.S. Middle East envoy, George Mitchell, has come and gone, again, with peace talks still on hold and one Israeli commentator, Yossi Sarid, musing that “the Israeli-Palestinian conflict is a black hole that swallows up goodwill ambassadors through the ages.”

I can’t argue with that. Cold wars come and go, new technologies transform the world, but the clash of Zionism and Palestinian nationalism in the Holy Land defeats resolution.

Right now, Israeli Prime Minister Benjamin Netanyahu thinks Palestinians are “up a tree” (a eucalyptus tree, to be precise) and Palestinians think Netanyahu’s a deceitful bully (the lead Palestinian negotiator, Saeb Erekat, characterized his tone as, “Come here, boy, we know what’s best for you.”)

Feeling optimistic already? I confess I am — or rather, the complete despair about the “peace process” with which I arrived in Israel has eased. O.K., that’s not exactly optimism, but in the Middle East small mercies count.

Mitchell’s trip was not unproductive. My understanding is that proximity talks will start again next month, with Mitchell’s team shuttling between the sides. Israel will refrain from provocations of the Ramat Shlomo kind (those planned 1,600 housing units in East Jerusalem) and will promise to get substantive, on borders above all. Palestinians will promise to, well, show up.

But that’s not the reason for my improved mood: It’s hard to celebrate proximity talks when Palestinians and Israelis have often held direct talks. No, I detect three developments. The first is Obama. The second is Fayyad. The third is what Danny Ayalon, the deputy Israeli foreign minister, called “the sugar-coated poison pill” of the Israeli status quo. I’ll take them in order.

Last week, a letter from President Barack Obama was conveyed to Mahmoud Abbas, the Palestinian president. In it, I understand, Obama spoke of his very strong commitment — unprecedented commitment — to a two-state peace and said that if Israel seriously undermines trust between the two parties, the United States will not stand in the way of a United Nations resolution condemning that.

No American definition of what such trust-undermining acts might be was offered, which is why Erekat pressed Mitchell in their meeting last Friday on what would constitute “provocative actions” by Israel.

But it seems clear that any reprise of the Ramat Shlomo debacle, which infuriated Obama, would meet American criteria. The bottom line to Israel is: Hold the building, hold the tenders and hold any other provocations while Mitchell shuttles.

Obama’s recalibration of U.S. Middle East diplomacy is ground-shifting. He’s being pummeled from the usual quarters but he’ll stay the course because he’s a realist and because soldiers have told him that, with 200,000 plus American forces in Muslim countries, getting to Israel and Palestine living side-by-side in peace is a vital U.S. national security interest. Calculation, not conscience (although there’s a little of that), is driving policy.

There’s real change in nascent Palestine, too. Salam Fayyad, the Palestinian prime minister, is the most important phenomenon in the Middle East.

Fayyad is obsessed with security — an obsession reflected in the now ubiquitous Palestinian Authority police on the West Bank — and with building state institutions and the economy. He’s not interested in Palestinian “victimhood.” Narratives do not a family feed. He wants a future. He believes nonviolence is the way to get there. He’s receiving some help from Netanyahu on the economy (but needs more) and security cooperation is ongoing.

Over time, Fayyad can reassure Israelis that they’ll get a reliable state over the border, not some Iranian Trojan Horse. Palestinian institution-building is the best answer to Israel’s “no interlocutor” argument.

Within Israel, a booming economy and day-to-day tranquility would suggest peace is a low priority. But polls show a majority feel the country’s moving in the wrong direction; rampant corruption scandals alone cannot explain that. As Ayalon told me, “We do not have an eastern border.” Countries without defined borders have a hard time believing they’re moving in the right direction.

That tells me Netanyahu has potential interest, Hamas and its vile videos about the kidnapped Gilad Shalit notwithstanding, in getting from status quo to permanent status.

Mitchell believes that. He was asked about Netanyahu during his visit and, according to notes I saw, responded: “I believe Netanyahu is serious, capable and interested in reaching an agreement. What I cannot say is if he is willing to agree to what is needed to secure an agreement.”

That meeting concluded with Mitchell saying: “You asked if I think Netanyahu is serious. They ask the same question. You are an expert on Palestinian and Israeli politics. They are the same. But no one in the world knows American politics better than me, and this I will say. There has never been in the White House a president that is so committed on this issue, including Clinton who is a personal friend, and there will never be, at least not in the lifetime of anyone in this room.”

Don’t give up just yet even if history, and Hamas, say peace is a pipe dream and Mitchell next in line for that “black hole.”