Published by New York Times, 18 January 2016

UNITED NATIONS — Barely a month after the world’s most powerful countries agreed to an ambitious road map to end the five-year-old war in Syria, there is still no agreement on who, if anyone, will show up at the peace talks that are supposed to begin in Geneva next Monday.

Instead, there are new worries that the talks will be pushed back, and with them any hopes for a cease-fire, as Syrians continue to die from shelling and starvation.

The new dispute revolves around the lingering question of who gets to represent the opposition delegation.

Saudi Arabia wants its handpicked rebel bloc alone to represent the opposition to the government of President Bashar al-Assad — and it has threatened to pull its proxies out of the process if others are added to the delegation, according to United Nations diplomats.

Russia, which supports the Syrian government, insists on a broader opposition bloc; otherwise, it has suggested, the government side would not attend. “Mutual vetoes on who should be invited,” is how one diplomat, who asked to remain anonymous because of the sensitivity of the talks, described the threats.

And so, barely a week before the talks are set to take place, the United Nations mediator, Staffan de Mistura, has yet to issue invitations and says he will do so only after world leaders iron out their differences over who can attend, diplomats said.

It is up to the United Nations to ultimately decide who can come, and those who impose new conditions risk losing out on the chance to have a seat at the table to discuss the future of Syria. A spokesman for the United Nations, Farhan Haq, hinted at the possibility of a delay in the talks, or “a slippage” in the dates.

The talks are part of a painstakingly assembled peace process negotiated by countries with deep stakes in the war, including the United States, Russia, Iran, Saudi Arabia and Turkey.

In a road map endorsed by the United Nations Security Council in midDecember, government and opposition representatives were instructed to discuss a negotiated settlement to the conflict, including a cease-fire and a plan to draft a new constitution and hold elections in 18 months.

On Monday, Mr. de Mistura told a closed session of the Security Council that the goal of negotiating a cease-fire remained a ways off, diplomats said, and that it was important instead to get the warring parties to lift sieges on key towns so food and medicine can reach people trapped there.

The United Nations has blamed the government for denying food and medicines from reaching about 180,000 people in rebel-held areas; it has blamed a rebel coalition for besieging about 12,000 people and the Islamic State for besieging another 200,000 people in government-held areas.

Harrowing reports of starvation deaths have emerged from the rebel-held town of Madaya in recent days, prompting the United Nations secretary general, Ban Ki-moon, to warn that using food as a weapon was a war crime.

As if to underscore the urgency, a group monitoring the conflict reported on Monday that the Islamic State had seized territory from government forces near the strategic eastern city of Deir al-Zour, and state news media said that 300 people had been killed in the assault.

The monitoring group, the Syrian Observatory for Human Rights, also said there was no word on what had happened to some 400 people it said had been abducted when the assault by the Islamic State began on Saturday.

In a telephone interview after his briefing to the Security Council, Mr. de Mistura insisted that the warring sides needed confidence-building measures before they could broach the idea of a broader truce.

“A national cease-fire remains the fundamental aim, but on the other hand it is clear that the warring sides are not yet ready for it,” he said by telephone from Geneva.

He called for “incremental and constant improvements in the reduction of violence until the talks produce an atmosphere for a national cease-fire.”

That there is a new disagreement over who sits at the opposition table should come as no surprise. In mid-December, there were intense negotiations over precisely how much influence Saudi Arabia would have in determining the opposition bloc.

Officials in Riyadh had convened a conference of rebel leaders the same month to pull together a broad array of opposition groups to take part in political negotiations.

That conference yielded a new bloc of political dissidents and rebel groups fighting the government, and it was meant to send a signal to Russia and Iran, the government’s main backers, that the opposition was not too divided to be trusted to make a deal.

The Saudi-sponsored delegation, however, did not include Kurdish rebels that Russia in particular had insisted be represented at the opposition table.

The question of who sits at the opposition table is as important as that other cloud that has loomed over the talks: the question of what happens to Mr. Assad. That has been kicked down the road.

The government delegation, according to a diplomat here, is to be led by someone many diplomats see as a polarizing figure: Bashar al-Jaafari, Syria’s ambassador to the United Nations. The diplomat, like others who discussed the Geneva talks, asked for anonymity to speak about sensitive negotiations.

The two sides are not expected to talk directly. At best, government and rebel representatives are to convene in separate rooms at the United Nations building in Geneva, with Mr. de Mistura shuttling back and forth.