Qardaha, a village in western Syria, is in the coastal Alawite state, where the Alawite minority sect is dominant and the 47-year-old Assad, who rose to power in 2000 following the death of his father, has many supporters.
A Russian source who met with Assad a number of times told The Sunday Times of London the president is ready to "fight to his last bullet," and could hold on for many months. The newspaper said Middle Eastern intelligence indicates Assad had moved seven Alawite battalions and one missile battalion, some equipped with chemical munitions, to Alawite territories.
Syrian Vice President Farouq al-Sharaa has called for a "historic settlement" to the 21-month-old conflict, which was officially labeled a civil war in July, the Lebanese newspaper al-Akhbar reported.
"The solution has to be Syrian, but through a historic settlement, which would include the main regional countries, and the members of the U.N. Security Council," al-Akhbar quoted al-Sharaa as saying in mid-December.
"The opposition forces combined cannot decide the battle militarily, meanwhile, what the security forces and the army units are doing will not reach a conclusive end."
It had been believed al-Sharaa defected to Jordan in August, but he later resurfaced in Damascus. Rebels have said they would support an interim government led by him.
"This settlement must include stopping all shapes of violence, and the creation of a national unity government with wide powers," he said.
Opposition forces, who began protesting for a more democratic government during the 2011 Arab Spring, withstood heavy shelling and air raids from forces loyal to Assad throughout the year and managed to take control of areas north and east of Aleppo, as well as the cities of Idlib and Bdama and surrounding areas in northwestern Syria, the Institute for the Study of War reported. In eastern Syria, rebels have taken much of Deir Ez-Zor province, except the capital, which is held by Assad's regime.
Damascus is predominantly under regime-rule; however, rebels have taken hold of some neighborhoods of the capital.
In November, under international pressure, rebel factions formed the National Coalition for Syrian Revolutionary and Opposition Forces, a united front made up of a 30-person Supreme Military Council. In exchange for unification, the main backers of the rebels -- Qatar and Saudi Arabia -- will be able to get money and weapons to fighters through the military council rather than trying to get supplies to individual groups.
The United Nations has steadily called for a cease-fire. In October, rebels and the regime agreed to stop hostilities for five days to mark the observance of the Islamic holiday of Eid al-Adha. On the last day of the cease-fire, activists reported more than 100 people killed in Damascus.
A cease-fire brokered by former U.N.-Arab League Joint Special Representative to Syria Kofi Annan in April also failed, with regime forces executing many civilians. Annan was seeking to resolve the conflict in Syria by implementing a six-point plan, but resigned his position in early August, citing both Assad and opposition unwillingness to cooperate. Lakhdar Brahimi was then named to replace him Aug. 17.
The United Nations said in December it is considering sending 4,000 to 10,000 peacekeeping troops to Syria at the request of Brahimi.
"The problem is that the U.N. has no extra resources. The U.N. has a contingent of about 115,000 peacekeepers in various countries, but in order to send [a peacekeeping mission] to Syria, [the United Nations] will have to withdraw them from somewhere," said a U.N. official, who spoke anonymously.
Since the start of the conflict in March 2011, more than 500,000 Syrians have been displaced, fleeing to neighboring countries such as Jordan, Turkey, Lebanon and Iraq, the U.N. Human Rights Campaign said in December. The death toll has reached about 40,000 people though independent confirmation has been hard to come by given the Assad government's refusal to allow journalists free access.
The Human Rights Watch in April documented the executions of hundreds of civilians and opposition fighters by Syrian security forces acting alone or with pro-government militia in the provinces of Idlib and Homs since December 2011.
"In a desperate attempt to crush the uprising, Syrian forces have executed people in cold blood, civilians and opposition fighters alike," Ole Solvang, emergencies researcher at Human Rights Watch, said in the news release. "They are doing it in broad daylight and in front of witnesses, evidently not concerned about any accountability for their crimes."
In Hama province, the Local Coordination Committees of Syria reported that Syrian government forces carried out the massacre of about 78 people in a small village in June.
Syrian state television said government forces sent to Qubeir following the massacre "raided a terrorist cell and killed a number of them and confiscated their weapons."
Government forces executed 108 people were killed in Houla on May 25, it was reported.
Syrian Foreign Ministry spokesman Jihad Makdissi blamed al-Qaida for the killings, saying: "We deny that the Syrian armed forces were responsible for what took place in Houla. There is no armed opposition in Syria. There is either an intellectual opposition, and we welcome their participation in national dialogue, or there are armed terrorist gangs that refuse the political resolution."
Turkey and other neighboring countries have voiced concern about fighting spilling into their countries. Turkish fighter jets were sent to the Turkey-Syria border in response to a Syrian helicopter firing near the Turkish town of Azmarin in October.
Most countries have expressed support for the opposition; the United States and other Western and Arab powers have said they plan to lend air and naval support to rebels.
"The United States will continue to aggressively pursue those who undermine the desires of the Syrian people to realize a representative government that does not employ violence against its own people. We will target the pro-Assad militias just as we will the terrorists who falsely cloak themselves in the flag of the legitimate opposition," Undersecretary for Terrorism and Financial Intelligence David Cohen said.
Meanwhile, China, Russia and Iran have backed Assad's government. Russian officials have said Moscow, a longtime ally of Syria, believes trying to overthrow Assad is a fruitless endeavor.
By year's end, however, support for Assad was waning.
"We're not fans of the Assad regime and we understand that it can hardly survive, but we also understand that's a decision for the Syrian people to make," said Dmitry Peskov, a spokesman for Russian President Vladimir Putin.
Iran's support for Assad was also weakened.
"Iran is trying to find other solutions so that Hezbollah would be able to get Iran's support even after the fall of Bashar Assad's regime," said a report by al-Arabiya at the end of November. "Iran is now establishing some connections with Syrian opposition figures without the knowledge of the Syrian regime as it doesn't want to give the impression that it has abandoned Assad."
Going into 2013, Syrian government officials and experts on the conflict suggested opposition forces could use chemical weapons against the Syrian people and blame the government, The Washington Post reported.
"It's almost inevitable [that rebels acquire chemical weapons]," Michael Eisenstadt, a retired Army officer at the Washington Institute for Near East Policy, told the Post. "It may have already happened, for what we know."
Maj.-Gen. Adnan Sillu, who defected from the Syrian army earlier this year, told al-Arabiya the Syrian regime has chemical weapons stored in facilities across the country and getting access to them would not be difficult.
"Syria's chemical arsenal has reached similar levels to Israel's nuclear weapons," he said. "Probably anyone from the Free Syrian Army or any Islamic extremist group could take them over."
Russia also warned that if rebels take control of the country, Syria's chemical weapons arsenal could fall into terrorist hands.
"The greatest danger is that parts of Syria continue to fall under the control of the opposition where extremists, terrorists and al-Qaida have strong positions," Russian Deputy Foreign Minister Mikhail Bogdanov was quoted saying by Russia's state-run news agency RIA Novosti. "That could have very serious consequences."
Bashar Ja'afari, the Syrian ambassador to the United Nations said he is "genuinely worried" that "terrorists could provide the armed terrorist groups with chemical weapons, and then claim they had been used by the Syrian government."
Meanwhile, the United States has warned against the Syrian government using chemical weapons against civilians.
"We are concerned that in an increasingly beleaguered regime, having found its escalation of violence through conventional means inadequate, might be considering the use of chemical weapons against the Syrian people," White House spokesman Jay Carney said during a media briefing. "And as the president has said, any use or proliferation of chemical weapons by the Syrian regime would cross a red line for the United States."
"The Assad regime must know that the world is watching, and that they will be held accountable by the United States and the international community if they use chemical weapons, or fail to meet their obligations to secure them," Carney said.