For al-Assad, full implementation of the plan, which includes a political settlement through dialogue and respect for the rights of citizens to demonstrate peacefully, will bring an end to his regime. From the onset of the uprisings, his government knew that a repeat of the protests in Egypt's Tahrir Square or Bahrain's Pearl Square in Damascus or Aleppo will mean regime change. Al-Assad and his inner circle are not about to create conditions that are conducive for such sit-ins just because the Annan plan calls on them to do so.
For the opposition groups, Annan could spend all the time he wants on negotiations, but any talks not predicated on al-Assad's stepping aside will not be acceptable. The activists who are spearheading Syria's revolution insist that the opposition exile leadership has a limited mandate and that is to discuss details for the transfer of power from the Assad family to the opposition.
The bottom line is that the two main protagonists in the conflict look at the Annan plan as a means to achieve their respective, mutually exclusive objectives.
By agreeing to the Annan plan, al-Assad pursues a dual-track strategy: He appeases his Russian and Iranian allies, who have been pressuring him to accept a political solution, while working to kill his way out of the crisis under the pretext that he is confronting "armed terrorists and gangs."
The opposition wants the cease-fire in order to field mass protests. As one activist from Hama put it to me recently: "We don't need military intervention, we don't need humanitarian corridors, we don't need safe areas. Enforce the cease-fire and millions will march toward the presidential palace demanding Assad's ouster."
After more than a year of uprisings, Syria is still stuck in a violent stalemate. Al-Assad has not been able to crush the opposition, and opposition seems nowhere near to dislodging al-Assad. Increasingly, the conflict is being framed in existential terms, with some involved becoming more radicalized.
The majority of Alawites believe their physical survival is at stake, because they are convinced al-Assad's demise will engender wide-scale revenge killings on them. Hence, they will not accept a solution that will produce a new regime in which they are not guaranteed a leading role. Similarly, the opposition groups believe that if they stop now and al-Assad remains in power, he will hunt them down.
Absent a game changer that will tip the balance in favor of one side or the other, the crisis in Syria will become a full-blown sectarian war pitting Sunnis against Alawites, which will likely spill over into the neighboring countries of Iraq and Lebanon.
Although military options have been considered by the West, it's hard to say whether that would make a difference in reversing the dynamics in the country. A military operation might cause a regional war involving Turkey, Saudi Arabia and Iran, with each country supporting its allies in Syria.
For now, Iran's Supreme Leader has cast his support firmly with al-Assad. A well-informed Iranian source told me that the Iranian regime will support al-Assad no matter what until the end. On the other hand, Russia's Syria policy seems to be in flux judging by its vote in the United Nations recently. It's too early to tell whether Russia will ease al-Assad out the way Saudi Arabia did in the case of Yemen's Abdullah Saleh. Russia and Iran will probably not abandon al-Assad until they are part of the deal-making process about Syria's future government.
One possible game changer is if the protest movement in Syria becomes widespread and covers large stretches of the country.
To date, only four of Syria's 14 governorates constitute the major hubs of the protest movement: Homs, Hama, Idlib and Daraa. While we have seen protests in other regions, they have not been as sustained and extensive as those in the four governorates. This is partly due to the state of fragmentation in the opposition ranks, especially among the exile groups, which do not inspire confidence among fence-sitters.
Randa Slim is a scholar at the Middle East Institute and a research fellow at the New America Foundation.
The above article was published in cnn.com on April 20th, 2012(12:11 GMT).