As anti-Syrian Lebanese mark the anniversary of the 2005 assassination of Rafik Hariri, allegedly by the pro-Syrian Hezbollah, Hariri's allies still face the threat of assassination as Lebanon remains in the grip of political turmoil.

This was underlined by the assassination last October of the head of the Internal Security Forces' intelligence branch, Brig. Gen. Wissam al-Hassan, a Hariri protege whose death closely resembled the bomb ambush that blew up Hariri's motorcade of armored limousines in downtown Beirut.

But while Hassan was a Hariri stalwart, there are indications his death wasn't necessarily part of the murderous fallout from the events of St. Valentine's Day 2005 but a fragment of a much wider conflict between Sunni and Shiite that Hariri's killing helped propagate.

Hariri, a self-made multi-billionaire and five times prime minister, was killed because he'd turned against Syria, which at that time had effectively occupied Lebanon for 29 years.

He was killed, along with 22 others, in a massive truck bomb that incinerated his motorcade of identical black Mercedes limos in a massive fireball.

Hariri's assassination was followed by a series of attacks, mainly bombings, on anti-Syrian figures, mainly politicians and journalists, in which several were killed.

Four others survived. One, Christian TV anchorwoman May Chidiac, lost an arm and a leg.

A U.N.-mandated international tribunal, the first to investigate a political killing, initially pointed the finger at Syria, which suited the Americans and the French who were great admirers of Hariri and his post-war reconstruction of Lebanon.

Damascus, a longtime practitioner of political assassination, denied the allegations but the killing of its adversaries in Lebanon continued, along with a wave of random terror bombings.

Eventually, Hassan's intelligence branch used cellphone records to track down the alleged killers and named four members of Hezbollah, including a top official of its secretive security apparatus.

Hezbollah denied involvement and branded the Special Tribunal for Lebanon as a U.S.-Israeli tool to discredit it. Hezbollah, Iran's powerful proxy on Israel's doorstep, has since its beginnings in the mid-1980s been dependent on Syria, Tehran's key Arab ally, as the conduit for its arms supplies and it's highly unlikely it would have carried out such a high-profile assassination on its own initiative.

The Hezbollah suspects were indicted by the tribunal, which plans to have a trial at its headquarters in The Hague. Hezbollah refuses to hand over the men.

Hassan's assassination in October eliminated a key figure in the Hariri investigation who in August had arrested former Lebanese Cabinet Minister Michel Samaha for smuggling explosives into Lebanon at the behest of Syrian intelligence to attack Syria's opponents.

On Feb. 5, Lebanese Judge Riad Abu Ghaida even had the temerity to issue arrest warrants for Brig. Gen. Ali Malmouk, a senior Syrian intelligence officer close to President Bashar Assad, for masterminding the plot.

But Hassan's killing was also probably a consequence of his links to Saudi Arabia's General Intelligence Directorate. It funds and arms the Sunnis and the ISF against Hezbollah, Iran's ally, in the wider sectarian war between the Sunni monarchy in Riyadh and Tehran.

The U.N.-led investigation into Hariri's assassination is pretty much complete. Everyone's waiting for the trial to begin in The Hague.

To be sure, other ISF officers had been assassinated before Hassan in what appeared to be a systematic effort to eliminate key figures in the ISF's intelligence branch, which is backed by the Saudis, Americans and the French.

One of Hassan's young officers, Capt. Wissam Eid, who traced Hariri's alleged killers through telephone records, was killed in a bombing Jan. 25, 2008, in what widely seen as an act of revenge.

His superior, Col. Samir Shehadeh, narrowly escaped death but was crippled in a bombing Sept. 5, 2006.

The ISF's intelligence branch is an elite Sunni unit sworn to fight the Shiite Hezbollah, and coreligionists Syria and Iran have infiltrated into the top echelons of the army and military intelligence.

But knowledgeable players in Beirut believe Hassan's murder was part of a plot by Syria's president, his back to the wall, to reignite Lebanon's sectarian conflict as a means to ensure his survival.

"By constantly raising the stakes for all concerned, Assad hopes he can somehow cling to power -- or take everyone down with him," observed international affairs commentator Simon Tisdall.