Libya's victorious revolutionaries now face a new threat: themselves.
The secular and the religious, the politicians and the militants all basked Thursday in the demise of a dictator after fighters killed Moammar Gadhafi and ended his four decades of repression in Libya.
But while congratulations poured in from across the world, the Obama administration and others tempered the celebrations with a dose of caution, conscious that Libya's formerly ragtag band of rebels must now avoid falling prey to extremists among themselves, or the type of political infighting that has hijacked the hopes of previous revolutions.
Gadhafi's death clears a cloud over Libya's shaky interim government while focusing new scrutiny on the former rebels and exiles now in charge and on possible candidates to lead a permanent government.
Despite a public embrace of Libya's transitional leadership, the U.S. remains leery of some of the motives of those who have promised a quick move to elections and democracy.
While no official said it, the fear of an Islamist surge in power hangs over Libya's unsure future.
"This is a momentous day in the history of Libya," President Obama declared from the White House Rose Garden.
"The dark shadow of tyranny has been lifted, and with this enormous promise the Libyan people now have a great responsibility: to build an inclusive and tolerant and democratic Libya that stands as the ultimate rebuke to Gadhafi's dictatorship. We look forward to the announcement of the country's liberation, the quick formation of an interim government and a stable transition to Libya's first free and fair elections."
The National Transitional Council's largely secular leadership has promised to respect human rights and the rule of law, and usher in an inclusive era of government, but it is held together by a shaky coalition of individuals with competing interests and ambitions. There is a massive power vacuum and uncertainty about what or who will fill it.
Armed groups across the country have emerged as laws unto themselves. Interim leader Mahmoud Jibril has indicated he'll step aside once Libya's liberation is complete, creating possibly another vacuum. And in a country awash in weaponry, where Gadhafi's once vast arsenal of conventional arms and rocket-propelled missiles have been looted, the threat of widespread instability is high.
Obama said the U.S. was "under no illusions."
"Libya will travel a long and winding road to full democracy," he said. "There will be difficult days ahead. But the United States, together with the international community, is committed to the Libyan people. You have won your revolution, and now we will be a partner as you forge a future that provides dignity, freedom and opportunity."
Libya's patchwork of competing tribal and regional loyalties makes it a challenging place to govern under any circumstances, and 42 years of idiosyncratic rule under Gadhafi compounds the difficulty. He drained the country of institutions, eliminated any threat to his authority and defined nearly all aspects of life through his political vision that centered on a green book, powerless "people's committees" and his unpredictable antics.
The U.S. has directed its diplomacy through a small group of Libya's ex-government officials, lawyers and economists with questionable influence on the streets. Washington has released only a fraction of the billions in Gadhafi assets it has seized, and it has hedged support for some of the Council's allies who are promising a quick move to elections and democracy but have spotty resumes.
"Nobody is in charge," said Anthony Cordesman, a security analyst at the Center for Strategic and International Studies in Washington. "You have a council that is barely able to work together, and you have militias with no chain of command. In the course of the next week or so, they are going to have to figure out how to govern."
State Department spokesman Mark Toner said the "tricky part" of the revolution begins now, adding that Libya's leaders should move rapidly "to establish control over the military" and "to establish control throughout the country."
"You've got militias, you've got units that have been very much involved in fighting, and it's a significant challenge how to bring them under a single command," he said.
Libya's fighters include both secular and religious Muslims, and their militias will almost surely demand a large role in Libya's governance. Some come with questionable pasts, having waged jihad against U.S. forces in Iraq or belonged to hard-line Islamist groups suppressed under Gadhafi's dictatorship.
With a third of the country impoverished, the U.S. and other Western powers are worried about what will happen if the jubilation of defeating Gadhafi turns to entrenched political frustration.
"My guess is that there will be more fighting," said retired U.S. diplomat Leslie H. Gelb.