Shifts in Syria pressure reluctant Washington
For two years, US President Barack Obama has been reluctant to get dragged into the fight in Syria. But with the conflict morphing into a full-fledged war by proxy, attitudes in Washington are slowly beginning to shift.
The situation in Syria has never looked more complex or intractable in two years of uprising and fighting. Plans for peace talks in Geneva remain in doubt.
Syrian President Bashar al-Assad continues to receive military hardware from Russia, and the Syrian rebels have accused Shia Lebanese militant group Hezbollah of "invading" Syria and bolstering Mr Assad.
Avoiding 'slippery slope'
Hezbollah, backed by Iran, has acknowledged publicly that it is backing the Syrian president.
Meanwhile, the EU has lifted its embargo on weapons to the rebels but no decision has been made by European countries to deliver arms.
The Syrian opposition is still struggling to come together.
It is easy to forget now that the Syrian revolution started in March 2011, when crowds of peaceful demonstrators spilled into the streets from Homs to Hama to Damascus demanding reform, freedom, and Mr Assad's departure.
But Mr Assad maintained most of his support within the elite merchant class, his own Alawite community, and among Christians.
In Washington, hopes that Mr Assad would just fall have alternated with diplomatic efforts for a political solution - anything that would avoid direct US engagement.
The administration still insists a political solution is the best option, but the dramatic developments on the ground are forcing it to reconsider its strategy.
"The president and those around him fear that taking some kind of a step might put them on the so-called slippery slope," said Fred Hoff, who spent months inside the administration's Syria debate and is now with the Atlantic Council in Washington.
"In other words, take one step and in the fullness of time you will be obliged to occupy the country. I think that's mistaken and I would not be surprised if the president himself has come to that conclusion."
Washington only this year sent non-lethal aid to the rebels - medicine and food.
Brian Sayers, a former Nato advisor, is now with the Syrian Support Group (SSG) in Washington, which helps deliver US government aid to the rebels on the ground.
Three deliveries have been made so far this year. On Mr Sayer's office wall, a map of Syria is covered with pink post-it notes listing the names of Free Syrian Army (FSA) generals and commanders with whom SSG is in contact.
"To have [non-lethal] aid that would go directly to the FSA, the Supreme Military Council, that was, I think, a very symbolic shift here in Washington," said Mr Sayers.
"This is the beginning of a process, and some people may be seeing this as a pilot project for how things move forward in the future."
In May, the Senate foreign relations committee approved a bill authorising the arming of carefully vetted Syrian rebels.
The committee's Democratic chairman Senator Robert Menendez once opposed arming the rebels, but now says it has become clear the cost of inaction is simply too high.
"Unless we are willing to sit back and watch another 80,000 be slaughtered, unless we are willing to sit back and see a failed state, unless we want chemical weapons to get in the hands of terrorists, we have to change the dynamics in Syria," he said.
"And we have to find a way to have either Assad and/or the Russians recalculate their thinking."
Fraught with peril
It could be months before the legislative process turns this bill into law. Even then, the administration may not decide to go down that route.
The president has already rejected a plan to arm the rebels, presented to him last summer by then-Secretary of State Hillary Clinton and then-CIA Director David Petraeus.
That proposal was made before radical elements in the rebellion - like the al-Nusra front - became as visible as they are now.
For now, the US will rely on others like Qatar, Turkey, and potentially European allies to supply the rebels with weapons.
Arming the rebels is fraught with problems, just like every other option under debate, from strategic strikes to no-fly zones and covert operations.
Mr Obama recently said he had asked his military to prepare additional plans for Syria.
Tired of war
US military intervention, however limited, would likely have to be conducted outside of a UN mandate because Russia would veto any resolution.
But so far, no efforts are underway to gather a coalition of willing European and Arab allies. And Mr Obama has said there would be no unilateral American military action.
Iraq and Afghanistan weigh heavily on this war-weary and war-wary nation. And the president knows there is little appetite in his country for direct intervention in Syria.
On the Memorial Day holiday, Americans paid tribute to those who had died in combat, and at parades in Washington many said they were apprehensive about involvement in Syria.
"Our own economy is hurting so bad right now," one woman said, "and I don't know how much more money we can dish out to help other people without helping ourselves."
Another added: "We've been in Iraq for a long time, and it's not like we don't sympathise with the plight of the people in Syria. On a whole we're so tired of war right now."
'US leadership needed'
But just as America's view of its role in the world is changing, so are perceptions overseas of what the US can or should do, and how much.
Mohammed Ghanem, a young Syrian professor from Damascus University, is in the US now lobbying for support for the opposition.
"We're not asking for boots on the ground," he said. "We're not asking for an Iraqi-style intervention, we're not asking for a full scale invasion.
"Syrians are fighting and sacrificing their lives in order to attain freedom. What they need is just some assistance because it's not a fair fight.
"What we need is leadership from the US. What is required in Syria is minimal assistance that can go a long way."