What is the background to the power struggle in Lebanon?
The incident that arguably solidified the Lebanese into two opposing camps was the assassination of Rafiq al-Hariri, a former Lebanese prime minister, in February 2005.
During his second term as prime minister, al-Hairi allegedly made it clear to Syria that he wanted Lebanon to manage its own affairs.
At the time, Syrian security forces and intelligence agents were maintaining a physical presence in Lebanon, which had begun in 1978 during Lebanon's civil war.
Accusations surfaced after al-Hariri's assassination that Syria had a hand in the killing.
Thousands of people took to the streets of Riad al-Solh Square in downtown Beirut on March 8, 2005, to show their support for Syria, while making it clear that it was time for Damascus to re-assess its presence in Lebanon.
The demonstration was organised by Hezbollah, the Shia organisation and armed resistance movement linked to Iran and Syria.
Thousands of people filled Martyrs' Square in the capital less than a week later, accusing Syria of killing al-Hariri and calling for Damascus to pull its forces out of Lebanon.
This led to the creation of the March 14 movement, in almost direct opposition to that of March 8.
Syria pulled its troops out of Lebanon in April 2005 and Lebanon's political parties coalesced around the March 8 and March 14 movements.
Which parties are involved?
The March 14 Forces, the majority bloc in the Lebanese government, is ranged against the opposition March 8 and Free Patriotic Movement.
The main players in the majority are the Future Movement (al-Mustaqbal), the Progressive Socialist Party (PSP), the al-Kataeb (Phalange) party and the Lebanese Forces, although there are many others.
The Future Movement, led by Saad al-Hariri, the son of Rafiq, is the largest party within the majority.
After general elections in June 2005, Saad al-Hariri had the option of becoming Lebanon's prime minister (a post reserved for a Sunni Muslim under Lebanon's political system). He instead appointed Fouad Siniora, a former finance minister.
Hezbollah, a Shia Muslim organisation, is by far the largest group within the March 8 opposition, but Amal, its former rival, is a key partner.
The Free Patriotic Movement, a mixed organisation which advocates a secular future for Lebanon, signed a Memoradum of Understanding with Hezbollah in October 2005, although it is not part of the March 8 coalition.
The Syrian Social Nationalist Party is also sympathetic to Lebanon's political opposition.
What are the more immediate causes of Lebanon's current political crisis?
There has been continued wrangling over power sharing following al-Hariri's assassination.
Hezbollah has sought greater representation in the cabinet since the general elections in 2005. It wanted a third of the posts available in the cabinet.
March 14 have said that Hezbollah wants a third of cabinet positions so that it can veto key decisions made by the executive.
|Hezbollah will continue to be a potent political
force in Lebanon [AFP]
Shia ministers from Hezbollah and other political groups pulled their ministers out of the cabinet in November 2006.
Supporters of the March 8 and Free Patriotic Movement pitched tents outside Siniora's office in Beirut to protest that they are not being represented in government.
Several members of the March 14 bloc have been killed or injured in attacks amid the arguments over the division of political power.
Walid Jumblatt, the leader of the PSP, has accused Syria and its "proxies" in Lebanon (such as Hezbollah) of leading a systematic campaign to reduce the March 14 bloc below the number of MPs needed to keep their majority in parliament.
Damascus and the opposition in Lebanon deny Jumblatt's claim.
The differences over power sharing were so entrenched that Lebanon was without a president (a post reserved for a Maronite Christian) since November 2007.
Michel Sleiman, a former army chief, was given the position, and sworn in upon the signing of the political agreement made in Doha, the Qatari capital, in May, 2008.
Another cause for the political battle was Israel's war in Lebanon against Hezbollah in the summer of 2006.
After standing up to Israel's military might for a month, Hezbollah declared a "divine victory".
Its leader, Hassan Nasrallah, became the latest hero of the Arab street and his movement was keen to leverage its success within Lebanon itself.
It stepped up the pressure on the government of Fouad Siniora, which it said was "illegitimate" and a "tool of the West".
Does the political crisis in Lebanon have an international dimension?
As ever in Lebanon, the answer is yes.
The United States and its key Arab allies, Saudi Arabia and Egypt, support the Siniora government.
Iran and Syria back the Hezbollah-led opposition.
The current crisis is not just a battle for control of one small country, but a wider regional battle between pro- and anti-Western forces.
This interplay of internal and external interests creates instability in Lebanon and the wider region in an unending cycle.
Iran and Syria would regard the curtailing of Hezbollah as an unacceptable victory for the US and its allies.
In turn, Washington, Paris, Riyadh and Cairo would see a victory for Hezbollah as being tantamount to handing over Lebanon to Iran.
Is Lebanon's identity crisis a fundamental problem?
Ever since its creation after the First World War, Lebanon has had a fundamental problem of identity.
Is it Arab or non-Arab? Should it look East or West? How should its mosaic of 18 religious communities share power?
The nation's elite attempted to share power by putting together the National Pact of 1943 which said the president would be a Maronite Christian, the prime minister a Sunni Muslim and the speaker of parliament a Shia Muslim. Other posts were divided up along confessional lines.
The formula is still followed, but over time the essential consensus has eroded.
The Christians, originally a majority, have become a minority.
The dominant Maronite-Sunni alliance has been challenged by the historically marginalised Shia community, which has become the largest group in Lebanon.
However, this demographic change has not been officially reflected, given that the last official census in Lebanon was held in 1932.