The same day, Iranian national security chief Ali Larijani traveled to Baghdad on a surprise three-day visit apparently aimed at discussing security and the upcoming conference with Iraqi officials.

The United States welcomed Iran's decision to attend the conference, calling it a "positive" development. Secretary of State Condoleezza Rice hinted before Iran's announcement at the possibility of meeting directly with Mottaki on the sidelines of the conference. President George W. Bush later explained that Rice and Mottaki could engage in bilateral talks within the context of the multilateral event, though he ruled out separate public-level talks between Tehran and Washington. Things still could go wrong before May 3, and Mottaki could decide against attending the conference, but for now it looks like he will show up. Deputy Foreign Minister Mehdi Mostafavi said May 1 that, while Iran is ready to hold "discussions" with the United States, the conditions are not appropriate for negotiations.

The potential open engagement between the United States and Iran at the foreign ministry level would be the culmination of back-channel negotiations that started even before the United States led the invasion of Iraq. In other words, the Bush administration -- long after having scrapped its original deal with Tehran on the makeup of a post-war Iraqi government -- has reached a preliminary understanding with Iran's clerical regime on how the two sides will proceed with regard to stabilizing Iraq in the wake of the unexpected Sunni insurgency, the subsequent sectarian war and the involvement of Arab Sunni states in the fray.

The Sharm el-Sheikh conference, then, represents the launch of the formal process of hammering out a complex, multi-party deal to piece together the Humpty Dumpty that is Iraq.

The U.S.-Iranian back-channel talks were never going to result in a deal on how to divide Iraq; rather, they were a way for Washington and Tehran to work out their respective concerns about a future post-Baathist Iraq before taking the problem to the wider forum. The back-channel talks, which provide the context for the multilateral conference, will continue -- though the real deal will likely emerge from this wider forum.

Throughout the years of behind-the-scenes talks, the two sides have been unable to reach an understanding that balances the concerns of both with regard to Iraq's future. Iran does not want an Iraq with close ties to the United States -- one that threatens Iranian national security and Tehran's regional aspirations. Conversely, the United States does not want to see an Iraq dominated by Iran -- a situation that would allow Tehran to threaten the Arab states in the Persian Gulf/Arabian Peninsula, and thus U.S. regional interests. Moreover, the involvement of Sunni Arab states that feel threatened by the rise of Iran and its Shiite Arab allies has further complicated U.S.-Iranian dealings. Saudi Arabia, which has emerged as the leader of the Arab world, has been spearheading the move to counter Iran.

Complications aside, the Saudi efforts to insert themselves into the equation have given Washington a tool with which to counter Iranian moves. In fact, just as the Bush administration has used the Iraqi Sunni card to rein in the country's Shia (Washington has signaled to the Shia that it is willing to cut deals with the Sunnis, especially the Baathists), it has leveraged its alignment with the Arab states to contain the Iranians. While the United States needs Iranian cooperation to stabilize Iraq, the Iranians also need the United States to ensure that the Arab states and their Iraqi Sunni allies will not threaten Iranian interests.

The upcoming conference, therefore, is immensely important to all sides. The meeting represents a formal acknowledgement by all parties of the sphere of influence the Iranians and the Saudis will have in Iraq. Both Riyadh and Tehran want assurances that each other's respective proxies -- the Shiite militias and the Sunni insurgents -- will be restrained from creating security issues for them. In recent weeks, the Iranians have demonstrated they can get Shiite leader Muqtada al-Sadr's militia, the Mehdi Army, to more or less go along with the security plan. On the other hand, the Saudi announcement of the arrests of jihadist militants and the seizure of large sums of cash and weapons was meant as a reciprocating message that Riyadh, too, can rein in the jihadists who threaten the Shia -- and, by extension, the Iranian position in Iraq.

The general understanding has been that a U.S.-Saudi-Iranian deal could help stabilize Iraq -- the assumption being that Riyadh and Tehran have the ability to rein in their respective militias and insurgents in Iraq. Although ending the violence is beyond either country's ability, the Saudis and the Iranians are letting on that they can contain their fighters -- for a price. The Saudis want to ensure that Iraq's Sunni community has a sufficient share of the political pie in Baghdad so that, even with Shiite domination of the Iraqi state, the Iranians could not use Iraq as a military springboard into the Arabian Peninsula. For their part, the Iranians want assurances that the Sunni minority in Iraq never again will be in a position to threaten Iran's national security. More than that, however, the Islamic republic would like to be able to use its influence to pull strings within the Iraqi Shiite-dominated government.

This is the dilemma that faces the United States and the Sunni Arab states. They want to figure out how to acknowledge Iranian influence in Iraq's affairs, but still prevent Tehran from using such influence to enhance its power. Iraq's ethno-sectarian demography -- it is only approximately 20 percent Sunni -- is what scares Washington and its Arab allies. They are hoping, then, that ensuring the Sunnis a sufficient share of the Iraqi government will serve to check the Iranian/Shiite rise. To achieve that goal, however, the United States and Saudi Arabia would have to make a major reciprocal concession: acknowledging that a larger share of the pie will be in the hands of the Shia. This is one of the key reasons why reining in the Shiite militias has become a prerequisite for containing the Sunni insurgency.

This brings us back to the Sharm el-Sheikh conference, where Tehran is hoping the United States and its Arab allies acknowledge Iranian interests in Iraq in exchange for Iran's willingness to restrain the Shiite militias. The Arabs are willing to give Tehran the recognition it wants, though they are operating from a position of relative weakness and cannot trust that Iran would not use a relatively stable Iraq to extend its influence across the Persian Gulf.

Furthermore, although the Bush administration is downplaying the possibility, the Arabs are concerned that the political pendulum in the United States is swinging heavily in favor of an early pullout -- or major drawdown -- of coalition forces from Iraq. Since, in the long run, they cannot trust Washington to underwrite a deal with the Iranians, the Arabs are hesitant to sign a document that would effectively give Iran the room to maneuver as it pleases. This is the root of the Saudi reluctance to use its influence among the Iraqi Sunnis to help contain sectarian violence.

More important, however, Iraq's Sunni and Shiite communities are so internally factionalized (the Shia to a greater extent) that neither Tehran nor Riyadh is likely to succeed in shutting down the militancy. Moreover, the multiplicity of Shiite political and militant factions makes it difficult for Iran to keep all of them happy -- and thus on board with any deal it might be willing to cut. The continuing strife in the Shiite south, especially in the oil-rich city of Basra, is but one example of the problems the Iranians face in this regard.

Similarly, the Saudis cannot claim to speak for all the Sunnis. But even more problematic for Riyadh is that its best weapon against the Iranians is the jihadists, especially those affiliated with al Qaeda -- precisely those who pose a major national security threat to the Saudi kingdom.

The question, then, is whether the Saudis and the Iranians can actually deliver on a triangular deal involving each of them and the third main state actor in Iraq -- the United States. It would appear that their fears over their respective interests have forced them to deal with one another despite their apprehensions.

Ultimately, however, the three big players are negotiating a security deal that rests on the faulty assumptions that each side has enough sway over the various factions inside Iraq to make an agreement actually work.