|Saad al-Hariri, Rafiq's son, marks the anniversary of the killing with March 14 supporters [EPA]
The bomb blast that shook Beirut's seafront on February 14, 2005 also caused one of the most seismic shifts in Lebanon's post-civil war history.
Rafiq al-Hariri, a former prime minister and prominent businessman, died in the massive explosion, along with 22 others.
In the wake of the killing, thousands of al-Hariri supporters held rallies in Beirut, pointing the finger of blame at Syria.
Given that Damascus had thousands of troops and security agents in Lebanon and al-Hariri was a Lebanese nationalist who had allegedly fallen out with Syria, the possibility of Syrian involvement seemed logical.
Amid massive pressure from the Lebanese public, Syria ended its 29-year military and intelligence presence in Lebanon. Soon after, the United Nations called for an investigation into al-Hariri's assassination.
Now, after nearly four years, a UN tribunal has convened in The Hague as part of the investigation – but there are differences in opinion over the role the court should play.
Damascus has claimed that the US has used the UN probe to limit Syrian influence in the region, despite the lack of any conclusive evidence connecting it to the murder.
In Lebanon, politicians aligned with the March 14 bloc (a coalition of anti-Syrian political parties) have insisted that Syria is to blame for al-Hariri's death.
On the other hand, Hezbollah, a Lebanese Shia Muslim group that receives Syrian support, has opposed the formation of the tribunal.
As'ad AbuKhalil, a professor of political science at California State University, says that Lebanese opinions of the tribunal are largely split along sectarian and political lines.
"Within March 14, they have a message that 'we know for sure that the Syrians are behind the al-Hariri killing but on the other hand, let's find out what the tribunal will say', which proves to me that there is something political about this whole matter," AbuKhalil said.
"If you go to Shia areas, even after the al-Hariri assassination, many people there make the point: why are we only bothered, to the tune of millions of Lebanese taxpayers' dollars, to find the culprits of the al-Hariri killing when there have been thousands of Lebanese killed by Israel and they have nowhere near as much attention paid to them?"
The UN investigation is intended to be completely independent and Saad al-Hariri, Rafiq's son, has said that the March 14 bloc will support the tribunal's ruling whether or not it implicates Syria in the assassination.
However, analysts say that the case has nonetheless assumed a political dimension.
|Detlev Mehlis, the first IIIC commissioner, was accused of jumping to conclusions [EPA]
"A lot of people have their hopes pinned on this, particularly the people from the Bush administration [who were in power in the United States when Hariri was killed]," Joshua Landis, the co-director of the Centre for Middle East Studies at the University of Oklahoma, said.
"The neo-conservatives in Washington were hoping that this case would stop any effort to re-engage Syria."
The first reports from the UN International Independent Investigation Committee (IIIC) appeared to support claims by the Bush administration that Syria was involved in state terrorism.
Detlev Mehlis, the first commissioner of the IIIC, in October 2005 released an interim report which said that there was "converging evidence pointing at both Lebanese and Syrian involvement" in the killing.
Key to this assertion was the testimony from two witnesses, Husam Husam and Mohammed Siddiq, who claimed that Syrian and Lebanese officials had planned the attack on al-Hariri's motorcade.
But speculation that Mehlis was personally convinced that Syria was involved in the bombing arose when he released an electronic version of his October 2005 report.
Journalists who read the electronic report found that by clicking the 'undo' option in a word processor they could display the names of several Syrian officials alleged to be involved in the assassination plot. Yet the official version of the report, issued by the UN, did not name any individuals, for reasons that are still unclear.
The leak by Mehlis, whether deliberate or not, suggested that the investigation was swiftly heading toward the conclusion that Syria played an active role in the assassination.
Yet within weeks of the release of the October 2005 interim report, Husam and Siddiq's testimonies were found to be unreliable – Husam had attempted to sell his story to Lebanese news media, undermining his credibility, while Siddiq was arrested by the IIIC on charges of providing false testimony.
"If one reads the reports from the Detlev Mehlis era, you will find that the guy often jumped to conclusions," AbuKhalil says.
"Most interestingly, he threw so many darts in different directions. For example, at one point, Mehlis pointed toward the People's Front for the Liberation of Palestine-General Command [a group with a firm presence in most of Lebanon's Palestinian camps], then later said they were not connected. He undermined the credibility of the court."
With Serge Brammertz installed as the new investigation commissioner in January 2006, the UN inquiry continued in a more considered and studious manner.
The Belgian investigator's management of the inquiry was more low-key than Mehlis's approach. Over time, the impression that Syria was the main focus of the IIIC began to fade.
"When Brammertz and others came along later, he did not repeat any of this narrative – they erased the evidence that relied on various witnesses, the ones who said they had been coached by people close to al-Hariri," Landis says.
"That left us without the Syrian narrative. Subsequently, we have had the UN people come out and say that they were building evidence against some kind of criminal network."
"Shift in investigation"
According to an International Crisis Group (ICG) report on US engagement with Syria, the investigation has been gradually de-politicised in recent months - largely as a result of Lebanon completing its required investigative tasks for the UN team.
In an apparent acknowledgement that the Bush administration had originally sought to use the al-Hariri case to pressure Damascus, an anonymous US official told the ICG that the March 14 bloc, a US ally in Lebanon, can no longer assume that the tribunal will automatically deliver a damning indictment of Syrian complicity in the plot.
"In the last year there has been speculation among those who have studied the case that there has been a shift in the investigation towards looking at links between the [al-Hariri] killing and Islamic fundamentalist groups," AbuKhalil said.
"If that is the case, there is going to be a major blow to the stature and credibility of [the] March 14 [bloc]," he said.
It is not only the US and March 14 bloc that has been accused of trying to influence the UN investigation by making dramatic public statements.
Though Syria has in recent weeks moved towards rapprochement with Saudi Arabia, a staunch March 14 and US ally, Damascus has also sought to politicise the UN investigation, analysts say.
|Syrians accused the US of influencing the investigation [EPA]
"The fact that the Syrian official media tried to discredit the investigation is itself significant - they invented a story about Melhis's mother and planted false witnesses," Nadim Shehadi, an associate fellow on the Middle East and North Africa programme at Chatham House in London, said.
"The pro-Syrian opposition in Lebanon, namely first accused Israel of being responsible for the assassinations and then violently opposed the tribunal [by taking to the streets of the Lebanese capital Beirut in March 2008].
"There is concern about more violence in Lebanon if the tribunal comes close to conclusions involving Syrians," Shehadi said.
However, Landis says, Syria has a card to play if the tribunal does attempt to call Syrian officials to attend the courtroom in The Hague.
"Key to this tribunal is that it will not have the powers that the [IIIC] investigators had – they could demand that Syrian individuals testify. Now Syria has said that if there is any wrongdoing it will try people itself," he says.
Damascus has told the tribunal it is not required to deliver Syrians to The Hague.
Should Damascus refuse to co-operate, Landis believes the UN and The Hague investigators could turn to the Security Council and ask them to pass a resolution ordering Syrian compliance and possibly impose sanctions.
"That is going to be very hard because we are in a different political environment than we were under the Bush administration."
Tensions, challenges remain
While the tribunal deliberates over the investigation's findings, tensions between the March 14 bloc (and its international allies) and Hezbollah and Syria remain.
Lebanon is preparing to hold a parliamentary election in June after months of political discord between March 14 and Hezbollah.
The tribunal thus has a number of challenges. It has to provide an independent and credible judgment, while alleviating charges that it has been fatally disrupted by those seeking to influence it.
At the same time, those working on the tribunal have to be mindful that its final ruling could set Lebanon's various factions on a dangerous collision course.
"I hope the tribunal would act in an independent, professional way - totally disregarding any other consideration," Daoud Kheirallah, a professor of law at Georgetown University, said.
"There are people who suspect the tribunal may be a political arm of those who created it. This makes it compelling for all those who are involved, whether at the prosecution level or the trial level, to be totally independent and competent, with justice as the only objective."