Much is resting on the so-called Geneva II peace conference on Syria to end the conflict in the country.
The UN-backed talks, scheduled to begin on January 22 in Switzerland, are set to bring together representatives from both the government of President Bashar al-Assad and the Western-backed political opposition for the first time since the conflict began almost three years ago.
UN Secretary-General Ban Ki-moon has said the landmark conference would be "a mission of hope", adding that it was "unforgivable not to seize this opportunity" to end a war that has left more than 130,000 people dead and millions more displaced.
Following a year of deadly battles between forces loyal to Assad and opposition fighters, Moscow, which backs the regime, and Washington, which supports the opposition, agreed that there can only be a political solution.
In June 2012, officials from the US and Russia, along with other major powers, met in Geneva and agreed on a road map, known as the Geneva Communique, for Syria's political transition.
The document envisioned the establishment of a transitional governing body - agreed upon by both sides - in Syria with full executive powers that would oversee elections and put the country on the path to democracy.
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Since then, several attempts to bring together the two sides have failed, mainly because of disputes over who should represent the Syrian opposition and government in the talks and over Assad's future role in the country.
In November 2013, Ban announced a new date for talks: January 22. He called the Geneva II conference "a vehicle for a peaceful transition" that would fulfil Syrians' aspirations for freedom and dignity.
The goal of Geneva II would be to achieve an agreement between the government and the opposition for the full implementation of the Geneva Communique.
Where the Syrian government stands
The Syrian government confirmed that it would attend peace talks - but made it clear that it did not accept the opposition's demand that Assad steps down. In a statement, the Foreign Ministry said that those who supported Assad's removal from power should "wake up from their dreams".
The government also wants "the fight against terrorism" to be set as a priority in the upcoming talks.
Ending support for the "armed terrorist groups" in Syria is "crucial for any political solution to the crisis in Syria to succeed", the Foreign Ministry said in a letter sent to Ban. Officials often label all armed opposition groups as terrorists.
Syria's main opposition bloc, the Syrian National Coalition, voted on January 18 to attend the conference, following days of procedural disputes among its members.
Initially, the internationally recognised Coalition said it would only attend the talks if a number of conditions were met, including the release of political prisoners - particularly women - and allowing relief access to besieged areas. The bloc also said that it would not take part in the talks unless Assad vowed to stay out of the envisioned transitional government.
A week before the talks were set to begin, the Syrian government appeared to have made an effort to show goodwill by announcing that it was willing to swap prisoners with the rebels and was ready to take "a series of humanitarian steps" to improve the delivery of aid.
However, several politicians in the Coalition who reject the Geneva talks say they are doing so to reflect the wishes of fighters on the ground.
The commander of the powerful Ahrar al-Sham rebels, Hassan Abboud, has told Al Jazeera his group would not be bound by the outcome of the Geneva talks. "We see Geneva as a tool of manipulation," he said.
The leader of Jabhat al-Nusra, the "official" al-Qaeda affiliate in Syria, also told Al Jazeera his group would reject the outcomes of the conference. "Those taking part in the conference do not represent the people who sacrificed and shed blood... We cannot allow the Geneva II game to fool the nation," Abu Mohammad al-Joulani said.
Zahran Alloush, the head of the Military Committee of the the powerful coalition known as the Islamic Front, tweeted that he would ask the group's leadership "to endorse putting the participants of both parties in Geneva II on a wanted list".
The Syrian government's delegation will be headed by Foreign Minister Walid al-Muallem. Media reports suggest that Deputy Foreign Minister Faisal al-Moqdad, presidential adviser Bouthaina Shaaban and Syria's UN envoy Bashar al-Jaafari will also be part of the delegation.
Countries invited to attend the Geneva II talks:
Algeria, Brazil, Canada, China, Denmark, Egypt, France, Germany, India, Indonesia, Iraq, Italy, Japan, Jordan, Kuwait, Lebanon, Morocco, Norway, Oman, Qatar, Russia, Saudi Arabia, South Africa, Spain, Sweden, Switzerland, Turkey, United Arab Emirates, United Kingdom, United States
The opposition's delegation would be headed by Ahmad Jarba, the president of the Syrian National Coalition. Coalition member Ahmad Ramadan said the 15-member delegation will include two representatives of the country's ethnic Kurdish minority, two for rebels and two for opposition groups based in Syria.
A senior Coalition member told Al Jazeera that the delegations would be made up of eight members in total, five of which would be Coalition members and three others coming from other opposition blocs.
Delegations from 30 countries are expected to participate in the conference. They were invited by UN-Arab League envoy Lakhdar Brahimi.
It remains undecided whether Iran, a staunch ally of Assad's regime, would be among the attendees. The US says Tehran should not be invited because of its failure to sign the Geneva Communique. Russia would like to see Iran in the conference. Tehran said it would only attend if given an unconditional invitation.
Prospects of success
Leaders of major world powers say that Geneva II remains the best opportunity to pull Syria out of the cycle of bloodshed.
But the possibility of achieving any agreement is questionable, amid the fundamental disagreement over Assad's future role. The opposition wants Assad to step down. Regime officials maintain that Assad should lead any political transition - and have also alluded to the possibility of him running for president in the country's April 2014 elections.
Moreover, given that the commanders of the major rebel groups made it clear that they were not bound by the outcomes of the conference, any ceasefire agreement is unlikely to be reflected in reality.
Diplomats from major powers, nonetheless, insist that there is no alternative.
"There is a binary choice here," Hugh Robertson, the British minister of state for foreign affairs, told Al Jazeera. "You either put pressure on them and try to have a peace agreement in Geneva. Or you do not bother and the fighting continues...
"If Geneva fails, we stop, we understand why, we regroup and we try again."