When the Bush administration holds a meeting this week to formally relaunch the Israeli-Palestinian peace process, one uninvited guest will be looming large over everyone's shoulder: Iran.

Tuesday's meeting in Annapolis, Md., was once envisioned as a three-day conference to kick off the negotiation of final-status issues. It's now an incredibly shrinking 24-hour gathering, but its occurrence at all is in no small measure a result of the rise of Iran and its brand of radical Islam in the Middle East.

Consider how Iran plays into the picture for the following players:

•If President Bush has finally bought into a process he eschewed for seven years, it is not so much because he really believes now is a propitious moment for progress on peace. Instead, analysts say, Mr. Bush sees the need to contain Iran. He also sees how bringing Arab moderates to the table with Israel could work toward that goal.

•Saudi Arabia said it would attend a conference only if it addresses the core issues for establishing a Palestinian state. That won't happen, but still Riyadh will attend – in large part because the Saudis see as desirable any action that ties the United States into the region and challenges Iran's rise.

•And the attendance of Syria – something that both the Bush administration and Israel hoped for – reflects how Damascus is seeking to hedge its bets after having aligned itself increasingly with the regime in Tehran.

For the US, moderate Arab states, Israel, and the Palestinian supporters of Mahmoud Abbas, "finding a way to counter the threat from Tehran … is fueling this peace meeting more than any other factor," says Martin Indyk, a former US negotiator on the Middle East who is now director of the Brookings Institution's Saban Center on the Middle East in Washington.

Expectations for the Annapolis meeting, to be held at the US Naval Academy in Maryland's capital, are "lower than the Dead Sea," says David Makovsky, director of the project on the Middle East Peace Process at the Washington Institute for Near East Policy. Neither Israeli Prime Minister Ehud Olmert nor the Palestinian president, Mr. Abbas, is coming from a position of domestic political strength that would allow for compromise.

The best to be expected from the gathering may be a "road map-plus" formula, Mr. Makovsky says. Under such a scenario, the parties would formally agree to undertake steps – security measures on the Palestinian side, a settlement freeze and steps easing Palestinian living conditions for the Israelis – while launching final-status negotiations on issues like refugees and Jerusalem.

Still, the meeting will draw participants anxious for anything that might stall Iran's hegemonic rise in the region, Makovsky says.

The reputation of Iranian President Mahmoud Ahmadinejad has risen in the Palestinian territories and the region as he has advocated violence over accommodation to address the Palestinians' plight. He has also skewered moderate Arab leaders for agreeing to work with Israel on peace.

Secretary of State Condoleezza Rice, who has focused much of her attention this year on Iran containment, hopes to use the Annapolis meeting to "pull Syria out of Tehran's orbit," Makovsky says. As one Arab diplomat told Makovsky, the real purpose of Annapolis is to "take the Palestinian card out of Ahmadinejad's hand," he notes.

But not everyone is so sure the Annapolis meeting will have the desired geopolitical impact, while some even caution that it could end up playing into Tehran's hands.

"This is rigged for Iran to win," says David Wurmser, a former Middle East adviser to Vice President Dick Cheney.

The objective of Tehran and in particular Mr. Ahmadinejad is to stoke a "civilizational struggle," pitting a weak and compliant Islam that is tethered to the West against an aggressive and resurgent Islam, Mr. Wurmser says. In that context, it actually serves Iran's purposes if a "humiliated" Arab world joins Israel at the conference table and doesn't receive anything concrete in return.

If the Saudis, Egyptians, and Jordanians are seen to "march off to Annapolis to surrender" before the US and Israel, Wurmser says, "that could be a greater gift to the Iranians than anything else Iran could achieve."

Others are not so categoric, but do see cracks in Secretary Rice's strategy of containing Iran with a relaunched Israeli-Palestinian peace process.

The idea that a convergence created by a fear of Iran could compel the parties to make unprecedented concessions has "elements of truth," says Dennis Ross, a fellow at the Washington Institute for Near East Policy and former peace-process coordinator for the Clinton administration. But that vision, he says, fails to grasp another reality: that Iran's rise is seen by many in the region through the "prism" of the Sunni-Shiite divide.

One result of that particular perspective is that Sunni states like Saudi Arabia are still holding out the possibility of producing a bridge between Abbas's moderate Fatah organization and the radical Hamas, which took control of Gaza after it won elections in January. Hamas is a Sunni organization but has relied increasingly on support from Shiite Iran as the international community has sought to isolate it.

"The assumption that a common threat would produce a common approach faltered," Mr. Ross says.

The Annapolis meeting will actually kick off with a dinner at the State Department Monday, when Bush is to hold White House talks with Mr. Olmert and Abbas. Bush is also scheduled to wrap up the event Wednesday with further talks with the two key leaders.

The impact of Annapolis will really be in what comes after it, experts say. For clues on that, most will be watching for two things: who actually attends the meeting and what Bush says in the speech he will give in Annapolis on Tuesday.

Rice pressed hard for Saudi Arabia to send its foreign minister, Prince Saud al-Faisal, as a sign of its commitment to the process. He will attend, though somewhat grudgingly.

Likewise, the administration wanted Syria to send its foreign minister and publicly assured it that the Annapolis microphone would be open to them to put their chief concern with the Israelis – the occupied Golan Heights – on the conference table. But Syria's announcement that it will settle for sending its deputy foreign minister, Faysal Mekdad, reflects a hedging of its bets: While Damascus holds out hope for improved relations with Washington, and wishes to demonstrate some distance from Tehran, experts say, it does not to appear to be playing wholly into the US game plan.

As for Bush's speech, the key will be if the president sets out any kind of an agenda and timeline for the peace process – and if he outlines any of the tough issues to be addressed with specifics. Mr. Indyk of the Brookings Institution says he will watch for any mention of the "territorial compensation" the Palestinians can expect in return for the West Bank settlement blocks that Israel will not be asked to hand over to a new Palestine.

And then, what mention does Bush make of a follow-up agenda to Annapolis? Many ears will be attuned to any reference to a review conference by which point certain progress would be expected. Indyk says talk is already circulating of such a conference occurring in Moscow.

Noting that the US and the international community are basically "reinstating a process after seven years of not having a process," Ross says the crucial question will be: "What is the day-after strategy?"