President Obama has now called on Syrian President Bashar Assad to quit. But if he did, or if he is toppled, who would replace Assad?
There's no clear answer. Assad and his late father, Hafez Assad, have ruled Syria for four decades and have not tolerated anything that resembles a genuine opposition inside the country's borders.
"There is no opposition in Syria. There are opposition groups," said Lebanon's Wissam Tarif, who has been a prominent campaigner for democracy and human rights in the Middle East.
The problem, Tarif says, is that the emerging opposition groups are deeply divided, with no real plan of how the country would be run in a post-Assad era.
Tarif is currently in Beirut and has been documenting the deaths, injuries and detentions in Syria during Assad's harsh crackdown on protesters over the past five months.
Tarif has been in touch with those leading the protests, and he used to work with anti-government groups inside Syria. Those groups made no real progress until the Arab Spring turned much of the region upside-down. And they still lack unity and direction.
By some counts, there are at least seven Syrian exile groups, each with its own leaders and its own ideas about how the country should go forward.
Then there's the internal opposition, which has been criticized by some activists for being too close to the Assad regime.
And finally there are the young protesters who have taken to the streets. But Tarif says even they are divided and ill-equipped to provide real leadership.
"There's millions of people taking to the streets, willing to die for freedom. And it's a hell of a very difficult job. But it's not enough," he says, adding that the demonstrators "do not know how to do politics."
Call For Unified Council
Tarif says all of these groups need to work together on a transitional council. It would be something of a shadow government, similar to what the rebels have created in Libya. However, that Libyan council has been filled with friction recently.
Still, Tarif says the important thing is to create a council and start working on how to get rid of Assad, maintain stability and run a new country.
"They have a lot of political differences, they have a lot of different political visions, and they have to overcome it," he said.
Up to now, anti-government groups in Syria have preferred to remain decentralized. This made it more difficult for the Syrian security forces to track them down.
The Obama administration criticized the Assad regime for months, and on Thursday called for him to step down. Assad has given no indication that he'll comply. But Tarif says it's time for the opposition to step up, stop arguing and unify.
"Such leadership has to emerge. And it has to emerge yesterday. They don't have time," he says.
RENEE MONTAGNE, host:
Activist: It's Time For Syrian Opposition To Unify
And after months of slowly ratcheting up its criticism of Syrian President Bashar al Assad, the U.S. yesterday finally called on him to step down. U.S. officials are imposing new sanctions and they're also thinking ahead to who might lead a post-Assad Syria.
NPR's Kelly McEvers spoke to one close observer of the uprising in Syria about how far the opposition needs to go before it could actually assume power.
KELLY MCEVERS: Wissam Tarif is a longtime campaigner for democracy and human rights here in the Middle East. Lately, he's been documenting the deaths, injuries, and detentions in Syria during the five-month crackdown on anti-government protesters. He's also been in close touch with those who are leading the protests. Tarif himself used to work with anti-government groups inside Syria. Those groups made little progress over the years until the Arab Spring, and the latest uprising. But still, Tarif says there's a problem in Syria's anti-government movement.
Mr. WISSAM TARIF (Executive Director, Insan): There is no opposition in Syria. There are opposition groups.
MCEVERS: Opposition groups that are many, Tarif says, and divided. First, there's the so-called outside opposition, Syrians living in exile. By some counts there are at least seven of these groups with different leaders and different ideas of how the country should go forward. Then there's the inside opposition. People criticize them for working with the current regime. And finally there are the youth protesters who've taken to the streets. Tarif says even they are divided and ill-equipped to lead a real political opposition.
Mr. TARIF: There's uprising. There's millions of people taking the streets, willing to die for freedom. And it's a hell of a very difficult job. But it's not enough. This is people who do not know how to do politics.
MCEVERS: Tarif says the next step is for all these groups to agree on a single transitional council, a shadow government like the rebels created in Libya. No voting, no arguing, Tarif says - just name a council and start working on how to get rid the regime, maintain stability, and run a new country.
Mr. TARIF: They have a lot of political differences, they have a lot of different political visions, and they have to come over it.
MCEVERS: Up to now, anti-government groups in Syria had preferred to remain decentralized. That made it more difficult for security forces to find them and crush them.
Mr. TARIF: They have killed some activists, yes. They have detained a lot of political leaders, yes. But we haven't seen assassinations for the opposition side so far at a big scale. No one has supported that. Therefore the leadership is not hiding. There is no leadership so far.
MCEVERS: Now that the U.S. has called for President Assad to step down, Tarif says it's time for the opposition to step up, stop arguing, and unify.
Mr. TARIF: Such leadership has to emerge, and it has to emerge yesterday. They don't have time. And I think they will do it. And it's just matter of assuming responsibility.
MCEVERS: Kelly McEvers, NPR News, Beirut. Transcript provided by NPR, Copyright National Public Radio.