Beirut's latest political murder may dampen hopes of US talks with Syria and shockwaves could short-circuit a US drive for a new Middle East with Lebanon as a "crown jewel," analysts said.
While Lebanese Industry Minister Pierre Gemayel's killing will be felt most in the streets of Beirut and Middle Eastern capitals, its impact was already affecting US policy in the region on Tuesday.
An early casualty may be the idea of dialogue with US foes Damascus and Tehran expected to be mooted soon by a commission co-chaired by former secretary of state James Baker probing new strategy for Iraq.
"It is going to be much harder," said Joshua Landis, a Syria expert and co-director of Peace Studies at the University of Oklahoma.
In the wake of Tuesday's murder, US President George W. Bush showed no sign of moderating his tone to preserve a diplomatic opening, accusing Syria and Iran of fomenting "instability and violence" in Lebanon, though stopping short of apportioning direct blame.
Syria's embassy in Washington hit back, saying attempts to pin Gemayel's death on Damascus were a well-worn "charade."
Some analysts saw the killing as the latest step in a bid by the Iran and Syria-backed Shiite Hezbollah militia to topple the US-endorsed government of Lebanese Prime Minister Fuad Siniora.
Others divined an effort by Syria to prevent Siniora's government from endorsing a UN-sanctioned tribunal agreed on Tuesday into the killing last year of the late Lebanese prime minister Rafiq Hariri.
But with many diplomatic signals pointing to a desire by Damascus to go to the table with Washington, why would Syria initiate new tensions?
"I believe the Syrians ... know they will be implicated [by the UN tribunal] at a very high level ... they have to stop this," said David Schenker, senior fellow in Arab politics at the Washington Near East Institute.
Schenker said Syrian outreach to Iran and Iraq in recent days was consistent with past attempts to deflect diplomatic pressure, at a time when the screws were tightening on Syria at the UN.
Analysts also suggested the killing could be the work of rogue factions in Syria or its intelligence services, or even be score settling in Lebanon's fractured political jungle.
If the intent of Gemayel's killers was to halt the Hariri tribunal, it will fail, said Brookings Institution analyst Bilal Saab.
"Regardless whether the Americans are going to talk to the Syrians or the Iranians, the international tribunal is a top priority and there is no turning back on that," he said.
Gemayel's murder meanwhile threatened to sweep Siniora from power and raised fears here planned street demonstrations by Hezbollah could turn out to be the first shots in a new Lebanese civil war.
Even a peaceful collapse of the Siniora government would deal a severe blow to the US democratization agenda in the region, in which the Bush administration has invested significant political prestige.
Lebanon "certainly was the sort of crown jewel in the administration's Middle East portfolio, but they are going to have to regroup," said Schenker, who served Bush as a Pentagon Middle East advisor.
Bilal Saab said the failure of the Siniora government would be a "setback for the Bush administration."
"The Americans believe that this government is capable of advancing US interests -- the flourishing of democracy in the region -- and they see Lebanon an example of democracy taking its way," Saab said.