UN special envoy for Syria crisis Staffan de Mistura (3rd L) with representatives of the Syrian opposition at a meeting in Riyadh, on November 22, 2017
Beirut – 28 November 2017: A new round of talks to solve Syria's nearly seven-year conflict starts on Tuesday in Geneva after a string of military successes for government forces bolstered by a Russian intervention.
Previous rounds have yielded meagre results and the Syrian regime's inexorable territorial reconquest could drown out opposition calls for President Bashar al-Assad to go.
Here are the main players in the talks, which come after the divided opposition announced a unified negotiating committee, and as the conflict's new diplomatic masters Russia and Turkey push for a settlement.
Since the launch of negotiations on the Syrian crisis in Geneva in 2014, the Syrian regime has been represented by a delegation of political figures including its chief negotiator and UN representative Bashar al-Jaafari.
At this new round of talks, the government is in perhaps its strongest position yet on the ground, thanks to advances made possible by a Russian military intervention that began in 2015.
The government now holds 55 percent of the country, territory where most of the population lives, and has scored successes against both rebels and the Islamic State jihadist group.
The government delegation has always rejected opposition calls for Assad's departure, saying the leader's future should be decided by Syrians at the ballot box, and not during negotiations.
Instead, they propose discussions on a reworked constitution and parliamentary elections, and a "broadened" government that preserves the regime's core infrastructure.
The regime has so far refused to sit at the same table as the opposition, deriding some of its members as "terrorists" or saying they are too divided to represent a united negotiating partner.
And the government's upper hand on the ground makes it unlikely they will arrive at these latest talks in a mood to compromise.
For the last two years, the opposition has been primarily represented in Geneva by the High Negotiations Committee (HNC), which groups the key opposition Syrian National Coalition, as well as representatives of armed rebel groups.
Formed in December 2015 in Riyadh, the HNC has always insisted that Assad must step down at the beginning of any transitional period, with an executive body formed to oversee the following stage.
Backed by Saudi Arabia and the United States, the HNC presents itself as the sole legitimate political representative of the Syrian opposition.
But other opposition groupings have participated in talks on a separate basis, including the so-called Cairo and Moscow Groups, which the HNC accuses of toeing a more conciliatory line on Assad's future.
This month, the different strands of the opposition met in Saudi Arabia to form a new delegation to attend the upcoming Geneva talks.
For the first time, they agreed on the formation of a unified committee of 36 members from across the opposition.
Eight members are from the National Coalition, with another four each from the Cairo Group and the Moscow Group. There are another seven rebel representatives.
Other spots are taken up by independents and other opposition groups.
The committee must now choose which of its members will head to Geneva as part of a delegation headed by the HNC's Nasr al-Hariri, who has served as opposition negotiator in previous rounds of talks.
The committee's founding statement says it is willing to negotiate directly with the regime, though it continues to call for Assad's departure.The Moscow Group has said it has "reservations" on that part of the committee's platform.
The UN's special envoy on the Syria crisis Staffan de Mistura is an experienced diplomat who has joked that he suffers from "chronic optimism" despite the apparent intractability of Syria's conflict.
A dual Swiss-Italian national, he was named to a post once dubbed "mission impossible" by then-UN Secretary General Ban Ki-moon in July 2014.
He follows in the footsteps of two other seasoned diplomats, Algerian Lakhdar Brahimi, and former UN head Kofi Annan, both of whom quit after failing to make progress.
Since 2016, he has presided over seven rounds of talks in Geneva, sporting his trademark pince-nez and an old-world demeanour reminiscent of European diplomats from a century ago.
He has at times raised eyebrows with his unorthodox ideas and pronouncements, including offering in 2016 to personally escort jihadists from besieged Aleppo in order to ease the crisis there.