Lebanon has seen a growing division between opponents of Syria's influence over its affairs and those who still see Syria as a valued ally.
The BBC News website profiles the most prominent figures on each side.
Walid Jumblatt is the leader of Lebanon's most powerful Druze clan and heir to a leftist political dynasty based around the Progressive Socialist Party.
He is seen by many as the country's political weathervane - consistently emerging on the winning side through the twists and turns of the 1975-90 civil war and its troubled aftermath.
He was a supporter of Syria after the war but, since the death of strongman Hafez al-Assad in 2000, he has campaigned for Damascus to relinquish control. Jumblatt has spoken openly of the fear that he - like murdered former PM Rafik Hariri - may face assassination because of this stance.
He not only commands the loyalty of members of the Druze community - a secretive offshoot of Shia Islam whose adherents make up about 10% of the population - but is admired by members of other religious minorities in Lebanon.
Michel Aoun is a Christian Maronite former Lebanese army chief who has lived in exile since 1990 when Syrian-Lebanese forces crushed his rebellion.
Many supporters of the "Cedar revolution" - the protest in central Beirut calling for Syrian withdrawal - are also supporters of Aoun, who has continued to campaign against Damascus from his Paris home.
But his critics see him as a proponent of Christian supremacy in Lebanon.
He has said he will return to his homeland before elections this year, despite risking arrest for alleged offences during his period as a rebel prime minister and warlord.
A wartime president (1982-88), Amin Gemayel was seen as a more unifying figure than his brother Bashir, assassinated president-elect and leader of the right-wing pro-Israeli Christian Phalange movement.
But his powers to govern were severely circumscribed by the Israeli and Syrian occupation of most of his country.
He arrived back in Lebanon in 2000 after 12 years of self-imposed exile, to join the opposition to President Lahoud's pro-Syrian government. But he was expelled from the Phalange, which takes a more moderate view towards the Syrians now than in the past.
Gemayel hit the headlines in March 2003, when he launched a doomed eleventh-hour attempt to mediate a peaceful solution to the Iraq crisis.
He is now a member of the Qornet Shehwan group of Christian politicians dedicated to bringing about a withdrawal of Syrian forces
Patriarch of Lebanon's largest Christian minority, the Maronite Church, Nasrallah Sfeir has found himself both within the Syrian camp and outside it.
At the beginning of the 1990s he supported Syria's role against the rebel General Michel Aoun.
He began demanding Syrian withdrawal towards the end of the decade, before falling silent again just as anti-Syrian views were becoming more widespread.
He has backed the process whereby Damascus says it will withdraw its forces, but has also called for Lebanon to focus on its economic development rather than political rifts.
Despite high expectations from his own Christian Maronite community - and the backing of the military which he commanded in the post-war period - President Emile Lahoud has proved to be a weak and unpopular leader, taking his cue from Syria on most matters.
He was elected by parliament in 1998 after a Syrian-backed constitutional change - allowing public employees to stand for office. In 2004 Damascus steamrollered another amendment through parliament to give him a three-year extension in office.
This move triggered the current crisis that has split Lebanon into pro- and anti-Syrian camps. The divisions were exacerbated by the killing of Rafik Hariri in February, who had resigned from the prime ministership in protest over this issue.
As the chief of Hezbollah (the Party of God) - the Lebanese guerrilla force and the Shia Muslim community's dominant political bloc - Sheikh Hassan Nasrallah is probably Lebanon's most powerful citizen today.
Despite owing much to Iran and Syria for Hezbollah's original funding and its continuing logistical support, he has always assiduously played the Lebanese unity card.
Hezbollah took the credit in Lebanon for Israel's unconditional withdrawal from southern Lebanon in 2000. Since, Nasrallah has won plaudits by fostering national unity rather than indulging in Shia triumphalism.
This was particularly evident in the huge pro-Syrian rallies Hezbollah has organised - where not one of its distinctive yellow-and-green flags was visible in a sea of Lebanese red, white and green.
He rejects UN Resolution 1559, which calls for the withdrawal of non-Lebanese forces (ie Syria) and the disbanding of armed militias (ie Hezbollah), on the grounds that Syrian and Lebanese interests are linked and should not be decided by outside forces.
Omar Karami served as prime minister in the early 1990s and was brought back to the post in October 2004 when the billionaire businessmen and architect of Lebanon's post-war reconstruction, Rafik Hariri, fell out with his former allies in Damascus.
A lawyer by profession, he entered politics in 1987 after the death of his brother - the eight-time Arab nationalist prime minister Rashid Karami - who was killed in a bomb explosion on his helicopter while still prime minister.
He owes his position to backing from Damascus and is a staunch supporter of Syria's influence in Lebanon's politics.
Nabih Berri is speaker of the Lebanese parliament, the highest Shia Muslim position under the Lebanese national pact dating back to 1943, that allocates the presidency to a Maronite and the prime ministership to a Sunni Muslim.
As head of the Amal militia, whose stronghold is in his native southern Lebanon, Berri is seen as little more than a puppet of Syria.
The ascendancy of Hezbollah has eroded his position, but he remains a shrewd political operator and Damascus has continued to keep him at a comparable rank to his more illustrious Shia rival Nasrallah.