Syria decided to join other Arab states attending the Annapolis conference on Tuesday after the U.S. agreed that the future of the Golan Heights -- Syrian territory occupied by Israel since 1967 -- could be discussed.

According to an article on the Christian Science Monitor, Syria’s presence at Annapolis could boost stability in Lebanon, which is facing a potential power vacuum after its president left office with no elected successor.

The departure of Lebanese President Emile Lahoud complicated an already tense situation, which many Lebanese fear could explode into violence between supporters of Prime Minister Fuoad Siniora’s Western-backed cabinet and the pro-Syrian opposition led by the resistance group Hezbollah.

Many analysts now say that Syria‘s presence could stabilize Lebanon as it would mark the beginning of a new chapter in the icy relations between Washington and Damascus, a close ally of Iran.

"There's been a very clear link in the past two weeks between the Lebanon crisis and Annapolis," says Ibrahim Hamidi, the influential Damascus correspondent of the pan-Arab Al-Hayat daily. "It's part of a process that focuses again on the Arab-Israeli struggle. Definitely, it will have a positive impact on Lebanon."

[See video: The truth about the Annapolis summit (Part 1, Part 2)] 

• Lebanon’s political limbo

Lebanon’s political crisis deepened after President Lahoud, a staunch ally of Syria during nine years in office, said the country is in a “state of emergency” and handed security powers to the army before leaving office late Friday with no successor.

Lahoud’s departure was a long-sought goal of the government installed by the parliament's anti-Syria majority, or the March 14 block, which has been trying to put one of its own in the presidency. But the opposition have blocked lawmakers from electing a new president by boycotting ballot sessions, leaving parliament without the required quorum.

The battle over presidency put Lebanon into a very dangerous situation, with the two rival factions accusing each other of violating the constitution. It also raised fears of civil strife, including the possibility of rival administrations.

Tensions are palpable on Lebanese streets, with schools closed and hundreds of Lebanese soldiers and armoured vehicles deployed throughout Beirut to prevent trouble from breaking out, even though the two rival factions have so far refrained from escalating the situation.

The Lebanese parliament is now scheduled to convene next Friday for a sixth attempt to elect a new president.

The March 14 block had threatened to elect a president from their own block if no consensus candidate was found. Such a step would have provoked the opposition to launch street demonstrations and possibly even form a rival government. 

"The March 14 block knows that the balance of power is in favor of the opposition and Syria and Iran. They have to wait and see what the opposition move will be," says Sateh Noureddine, columnist for Lebanon's As Safir daily.

• Improved U.S.-Syria ties?

Many analysts believe that the outcomes of the Annapolis summit would influence politics in Lebanon, particularly if Syria emerges satisfied from the conference. 

Damascus’ ties with Washington have been frozen since the February 2005 assassination of former Lebanese Prime Minister Rafiq Hariri. An incomplete UN probe into the murder has implicated top Syrian officials in the killing and an international tribunal is being established to judge those eventually indicted for the crime.

Some observers think that Syria would seek a comprehensive deal that would restore its relations with the U.S., and restore its tense ties with other Arab states.

Émile Khoury, a columnist with Lebanon's An Nahar newspaper, predicts that Syria would offer to help stabilize Lebanon, and in exchange, the international tribunal "would not be used for political vengeance that puts the Syrian regime in danger."

But the Bush administration has been reluctant to open dialogue with Syria, even though calls for engaging with Damascus have been growing in recent months. 

Last month, Maj. Gen. Moshe Kaplinsky, the then-deputy chief of staff of the Israeli army, said at a conference in Washington that it was “time to use the carrot" not just the stick in dealings with Syria.

Syria should be engaged in order to “remove it from the axis of resistance”, he said, referring to the regional alliance grouping Syria, Iran, Hezbollah and Hamas that opposes Israel and U.S. policy in the Middle East. 

"This will stabilize Lebanon and reduce Iranian influence in Lebanon and Syria," he said, according to the Christian Science Monitor.

Now that Syria has been invited to Annapolis, many observers say that Washington is willing to change its stance towards Damascus. 

Although Syria isn't sending a high-level delegation to Annapolis, its presence alone has encouraged other Arab states to attend, boosting Washington’s hopes for a successful conference.

"The fact that the Syrians got what they wanted from Washington [on the Annapolis agenda] made the Syrians happy, and I think this will be part of a process of resuming dialogue between the two administrations," says Mr. Hamidi of Al-Hayat.

But Damascus’ decision to attend Annapolis irritated its allies, especially Iranian President Mahmoud Ahmadinejad, who said on Sunday “I am sorry that some people around us plan to participate in the conference which only helps to support the Zionist occupiers."

Amal Saad-Ghorayeb, of the Carnegie Endowment's Middle East Center in Beirut, says that Ahmadinejad's comment was "very strong language" and a "clear warning to Syria that if it makes concessions [at Annapolis] it will fall out of favor with Iran."

Meanwhile, Lebanese politicians -- who know that Lebanon has always been at the centre of a tug-of-war between world powers -- are awaiting the outcomes of the Annapolis summit, fearing that they could be sold out in a broader deal between the U.S., Syria and Iran.