Syrian army rocket launchers fire last month near the village of Morek in Syria. (Alexander Kots/Associated Press)

“Syrian peace talks” is one of those phrases where the soothing words don’t fit the nightmare reality. But the indefatigable Secretary of State John F. Kerry is making another try this weekend in Vienna, and there’s more to this effort than just his good intentions.

What’s driving this round of diplomacy is the hope that Russia needs a settlement of the Syria mess even more than the United States does. President Vladimir Putin intervened militarily, elbows out, in late September. But the campaign has been frustrating for Moscow, and Russia’s resources are limited. A gradual political transition may serve Putin’s interests.

Unfortunately, this Syrian peace process doesn’t include any Syrians yet. That would seem a fatal defect, but Kerry & Co. are working on the problem.

Kerry’s biggest achievement has been getting Saudi Arabia and Iran to sit down at the table with the United States and Russia. The Saudi-Iranian feud is at the heart of the Syrian conflict, which is in some ways a proxy war. This negotiation is at least a step back from the sectarian inferno.

President Obama has enlisted Sheik Mohammed bin Zayed, the military leader of the United Arab Emirates, in coaxing the Saudis to participate. The Iranians have been wary diplomatic partners, too. Iranian hawks don’t like the negotiations, but they seem to have been overruled by Supreme Leader Ali Khamenei, who doesn’t want Iranians coming home from Syria in body bags.

The Syria talks are proceeding in a careful, step-by-step process that’s as delicate as building a house of cards. Three working groups have been established to focus on the elements that would be necessary for de-escalation and eventual agreement.

The first working group is trying to define the common terrorist enemies shared by the United States, Russia, Iran, Saudi Arabia, Turkey and Europe. This enemies list has two obvious candidates: the Islamic State and Jabhat al-Nusra, the al-Qaeda affiliate in Syria.

The finesse point is deciding whether a militant Islamist group called Ahrar al-Sham, which is backed by the Saudis and Qataris but sometimes fights alongside the extremists, should also be on the blacklist. The United States and Britain seem willing to treat Ahrar al-Sham as a part of the solution, rather than the problem, if it behaves more responsibly. Ahrar al-Sham may determine by its actions which side it will be on.

Working group No. 2 is weighing who should represent the Syrian opposition if peace talks broaden. The opposition is a miasma of differing groups, personalities and agendas, so this isn’t an easy task. The United States and its allies have their roster of preferred groups. Russia has its own list of opposition figures who have been invited to Moscow for talks.

The challenge is to merge these lists without triggering a new round of feuding. One name that’s said to be on both U.S. and Russian lists is Moaz al-Khatib, a former leader of the opposition coalition. He’s a respected figure around whom a broader front might be constructed.

Staffan de Mistura, the U.N. special envoy on Syria, would probably oversee the discussions, if the opposition could agree on some basic positions. De Mistura has tried, without much success, to negotiate local cease-fires, but he is respected by both the opposition and some members of President Bashar al-Assad’s regime. If the stars are in alignment, it would be Russia’s job to push the Assad regime into the negotiations, too.

Assad’s tenure as president is the most divisive issue of all. Kerry got the negotiations rolling last month by persuading everyone to put the Assad problem in the “too hard” basket, for now. But it’s understood by everyone (including the Russians) that any viable peace process must lead to Assad’s eventual departure, within two years or so. Otherwise, it’s a dead letter.

The third working group is charged with what may be the most delicate issue — how to organize humanitarian aid if the other diplomatic cogs are in place. Delivery of assistance will be impossible unless there’s the equivalent of a cease-fire. The regime and opposition elements that agree to the cease-fire could then, in theory, work together (or at arm’s length) to defeat the common terrorist enemies.

Like any peace process that’s contemplated while a war is raging, this one is a series of “ifs” stacked on top of each other. But Kerry has made a start, and as he showed during the Iran nuclear talks, he is one persistent diplomat.

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