Iran’s meeting with six world powers on Saturday is seen as a last chance before possible runaway escalation in the crisis over Tehran’s alleged pursuit of nuclear weapons. As ominous as that sounds, the two sides are going into the encounter in Istanbul neither in a harsh mood of confrontation nor desperately insisting that an agreement must be struck. For their own reasons, each side wants to give diplomacy a chance at this point, to start a process rather than to force a quick fix.

Iran, its oil sales slipping under tough international sanctions, may or may not be considering trying to cut a deal on its nuclear program. The six powers, meanwhile, are wary of Iran’s willingness for serious talks and are themselves split by longstanding differences between the United States and Russia about how tough to be with the Islamic Republic.

And so, the decade-old showdown over Iran’s alleged pursuit of the bomb continues to unfold in slow motion, even if Iran’s atomic progress, Israel’s threats to stop this with an attack, and a harsh U.S.-led sanctions regime aimed at cutting Iran’s oil sales and crippling its economy make the current days feel like an endgame.

The last talks, in January 2011, also in Istanbul, ended with Iran imposing conditions—that all sanctions against it be lifted and that its right to enrich uranium be unquestioned—that left the so-called P5 plus 1 of Britain, China, France, Germany, Russia, and the United States unwilling to continue discussion. With diplomacy in a vacuum and Iran building a second enrichment site that could be invulnerable to an airstrike, talk of war grew. President Barack Obama brought diplomacy back when he met with Israeli Prime Minister Benjamin Netanyahu in Washington last month and said “loose talk” should stop and that there was still a “window” for negotiations.

Now Istanbul will be tried again.

So expectations for Istanbul are low, diplomats say. The goal is basically to have a second round of talks, whenthe real bargaining will begin.

As it heads into the talks, Iran is promising to cap its uranium enrichment at 20 percent, a level the United States says it won’t accept because it is too far along to making the raw material for a weapon. Still, this proposal is viewed in Iran as a concession. In addition, Iranian negotiator Saeed Jalili was quoted Thursday saying he would be coming to Istanbul with “new initiatives” and that Iran was ready to hold “successful and progressive talks on cooperation.” Iran insists its nuclear program is a peaceful effort to use atomic energy for civilian purposes despite U.S. charges that it seeks the bomb.

Is the international response to Iran’s seeming new openness a specific plan, a road map for going forward? Not yet. Beyond saying Iran must cut down much more on its nuclear work, the six world powers are stymied among themselves. They have failed to forge an agreement on what to offer the Iranians, and almost surely will not have one when they come to the negotiating table in Istanbul, the perfect spot for the talks since it is literally where East meets West, where the landmasses of Asia and Europe face each other across the waters of the Bosphorus.

One reason for this, beyond just cautiousness, is lack of unity, despite Washington’s dogged proclamations that the P5 plus 1 has a unified position. The fact remains that Russia and the United States have profound differences when it comes to Iran. Among these are that Russia does not think sanctions work, does not think an Iranian bomb would lead to nuclear proliferation in the region, and does think Iran should be coaxed rather than punished to get it to cooperate.

Iran, of course, has in the past used such divisions to delay actions against it and to use time to create facts on the ground, such as having thousands of centrifuges enriching uranium, which make its nuclear program harder to rein in. U.S. and European diplomats are committed to not let this continue. U.S. Secretary of State Hillary Clinton has said the Iranians “have to know that this is not an open-ended discussion.”  She said Thursday that while the United States is “receiving signals that they are bringing ideas to the table… we want them to demonstrate clearly in the actions they propose that they have truly abandoned any weapons ambition.”

Russian Deputy Foreign Minister Sergey Ryabkov gave a frank analysis in comments surprising for their straightforwardness, at a public event in Washington this week.  Ryabkov explained the dilemma of the P5 plus 1: “We do have unity of purpose, we do know what we want … But we, a few days before the next round in Istanbul, really do not have a common view on what’s the real offer to be made for the Iranian part, in order to bring it into serious negotiations.” He said that Russia had tried on its own last August to negotiate a deal with Iran, something the Western P5 plus 1 members had objected to as a threat to their united front. But even this breakaway effort failed because the Iranians want simultaneity, namely that a compromise by Tehran would be immediately matched by a reduction in sanctions against it by the international community. “There is no time gap between action on their part and counteraction on the part of E3+3 (another formulation for the P5 plus 1) and broader international community,” Ryabkov said. He said the U.N. nuclear watchdog should first certify that the Iranians have done what they said and also, that the United States is against a quick lifting of sanctions.

And so it is unlikely the United States and its five partners will come to Istanbul ready to lay a proposal on the table. More likely they will be listening to what the Iranians have to say about the spectrum of ideas that have emerged as the nuts-and-bolts of any deal—namely that the Iranians take major confidence-building measures to rein in their enrichment and in return the international community would begin to freeze or diminish pressure against the Islamic Republic. It is a phased approach, a step-by-step approach. The problem is making the first step, let alone in agreeing after that on exactly how to proceed. That first step might involve Iran allowing wider inspections of its nuclear program, but the United States will want 20 percent enrichment to stop, for work at the second, highly protected enrichment site at Fordow to halt, and for the uranium already enriched to 20 percent to be shipped out of the country. This is a very big first step that would already redefine the Iranian nuclear program. Further down the line is what to do about enrichment in general, and that is a huge, almost intractable issue.

Expectations for Istanbul are low, diplomats say. The goal is basically to have a second round of talks, when the real bargaining will begin. In short, if the Iranians engage in dialogue on the nuclear issue in Istanbul, then they will be considered serious about talks and there will soon be another round, apparently in Baghdad.

A senior European diplomat told me: “I don’t sense that our partners want to test the Iranians by making a precise proposal in order to see how the Iranians react.” He said this weakness must be turned into a strength, by talking about a spectrum of ideas and seeing how the Iranians join in the discussion. Said Ryabkov: “We’d rather have a kind of menu of ideas to offer and I think it’s useful and healthy in a sense that it brings Iranians into a kind of atmospherics where they simply have no other choice rather than to, in our view, respond logically to these offers and try to comment at least, what they believe is more useful, less feasible, which has more perspectives, and what they believe is completely out of question.”

Ryabkov added: “The whole difficulty with this round is that we need to bring them into serious discussions, to open up, to at least begin opening up their own cards …  Because it’s inadmissible, the interval between rounds amounts for a year and a half. Something like this cannot even be called negotiations or talks. These are very sporadic events. And it’s inadmissible because the whole situation has the tendency, very clear tendency in our perspective to deteriorate.”

If the Iranians block discussion, as they did in the last meeting in Istanbul, then the talks will fail. If the Iranians, however, use the lack of specific demands on the part of their negotiating partners as a chance to begin the process toward finding common ground, then the bargaining can begin.

This article originally appeared on The Daily Beast.