FP asked five smart observers to offer their solutions for the quagmire in Damascus.

Last week's massacre in the Syrian village of al-Houla, in which more than 100 civilians lost their lives, has called into question the conventional wisdom in Washington that intervention would make things worse on the ground. President Bashar al-Assad's disregard for the U.N. deadlines in early April to withdraw forces from populated areas and implement a ceasefire has further undermined whatever credibility anyone thought he had.

Without leadership from the United States, though, there is little hope that the many countries with a stake in Syria's conflict will support a negotiated solution. The only way Russia would be willing to help pressure the Assad regime to "step aside," as the White House has demanded, would be if Moscow assesses the regime is in terminal failure and Russia's interests in the Middle East are at stake. U.S.-led intervention sooner, rather than later, would help accelerate that process. The question, however, is how and when. Beyond the existing diplomatic isolation, the sanctions regime on Syrian oil exports and other designations of Assad regime figures and entities, a number of measures could be undertaken in the short run to weaken Assad's grip on power. Here they are, in order of most indirect to most direct:
 
1. Provide greater support to the opposition within Syria: The Obama administration is providing non-lethal assistance to the non-violent opposition in Syria. That assistance could be extended openly to all opposition forces as well, including providing them with vital intelligence about regime security and military formations headed for towns and cities. Working with these groups would help the United States understand them better, assess their reliability, and establish bonds of trust that could lead to provisions of lethal assistance as the conflict unfolds.
 
2. Encourage the Kurds and Arab tribes in eastern Syria to fully support the uprising: The Assad regime has broken its most reliable divisions into brigades as it continues its deadly game of "whack-a-mole" with the Syrian opposition. One way to further stretch Assad's forces and accelerate its demise is to expand the Syrian uprising to eastern Syria, where Syria's Kurds and Arab tribes hold sway. They also sit atop Syria's oil and gas producing regions. Sabotage operations on pipelines and other facilities would severely constrain the regime's ability to maneuver. In preliminary discussions with figures representing these communities, they have expressed interest in expanding their relationship with the Free Syrian Army, which has been active in eastern Syria. Now is the time to take the next step.
 
3. Help Syria's neighbors create safe zones on their territory: Official figures show Syria's border areas in Turkey, Lebanon, and Jordan hold around 70,000 displaced persons, with unofficial figures undoubtedly much higher. Washington could help all three countries create de facto safe zones that could serve as staging areas for the training and equipping of all aspects of the Syrian opposition, including military. This is a legitimate possibility in Turkey and Jordan (with U.S. backing), though it is highly doubtful that it is feasible in Lebanon given Hezbollah's influence. Sunni and Kurdish areas of Iraq could serve as future buffer zones as well.
 
4. Help create buffer zones within Syria: Safe zones and staging areas in Turkey and Jordan, once established, could be extended onto Syrian territory to protect civilians and allow the Syrian opposition to operate freely within Syrian territory. Turkey has already reportedly developed detailed contingency plans to establish such a zone or zones as a way to deal with refugee flows and to keep Kurdish militants, which the Assad regime supports, from entering Turkey and carrying out attacks. Establishing such zones would involve a long-term military commitment by Turkey and its allies that would only be sustainable with U.S. assistance.
 
5. Establish an arms quarantine off the Syrian coast: Iran and Russia are openly sending arms to the regime, and this needs to stop. The United States and its allies could establish a naval quarantine along Syria's coastline similar to the international patrols that intercept arms shipments to Lebanon destined for Hezbollah. This, however, would seem to require a U.N. Security Council resolution -- which Russia would likely veto. A possible way around that could be to establish a naval and/or air quarantine of Syria with legal support from the Arab League, akin to the legitimacy given by the Organization of American States to a similar measure during the Cuban Missile Crisis. The question, however, is what happens when Russia and Iran challenges it.
 
As Syria's conflict tragically unfolds, Washington may need to carry out surgical airstrikes or similar measures to stop regime forces from attacking civilians. If those strikes are to succeed in toppling the regime, however, Washington and its allies will need to have cultivated an alternative leadership from the fragmented Syrian opposition. Conflict will be the constant in Syria for the foreseeable future. But conflict does not necessarily have to set off a generalized civil war -- the opposition on the ground has come together over one issue: Assad must go at all costs. The question is how to get there.
 
Andrew J. Tabler is a Senior Fellow at The Washington Institute for Near East Policy and author of In the Lion's Den: An Eyewitness Account of Washington's Battle with Syria.