The U.S. and Saudi Arabia are stepping up diplomatic efforts to find a solution in Syria, eager to prevent Russia and Iran from deciding who rules that nation if Bashar al-Assad is driven from office.
As Secretary of State Hillary Clinton and other world leaders huddle Saturday in Turkey to discuss post-Assad Syria, U.S. leaders and their closest allies in the region are increasingly concerned about Russian and Iranian influence.
The State Department is sponsoring multiple efforts aimed at crafting a road map for identifying potential government officials to oversee the country if and when Assad leaves office. And Saudi Arabia is hosting an Organization of Islamic Cooperation meeting next week in Mecca where world leaders, including Iranian President Mahmoud Ahmadinejad, will discuss what should be done about Syria's 17-month civil war.
[Photo Gallery: Fighting Continues in Syria.]
"The U.S., the Saudis and their allies are saying, 'We're in charge here,' rather than allowing Russia or Iran to take the baton," one source says.
Iranian leaders, who were not invited to Saturday's meeting in Turkey, are holding their own meeting that reportedly will feature officials from about a dozen countries.
Given Iran's increased diplomatic talk and actions, "the U.S. very much wants to be seen at the forefront of the diplomatic effort," the source says.
Russia has ample sway inside Syria due to its decades-long relationships with Assad and other power brokers. Tehran is Assad's only other remaining ally, and also has deep influential relationships; Shiite Iran is fearful Syria will become a nation ruled by rival Sunni Muslims.
The high-level powwows will take place as fierce fighting wages in the key Syrian city of Aleppo, a former rebel stronghold that in recent days appears to now be back under the control of Assad's military forces. The Associated Press reported Friday that government aircraft continue to bombard rebel targets inside Aleppo, triggering a fresh wave of citizens fleeing not just that city but their native country, as well.
As Assad's aircraft pounded Aleppo, members of the opposition made fresh pleas for the international community to provide them with heavy weapons like anti-aircraft guns.
"The warplanes and helicopters are killing us, they're up there in the sky 15 hours a day," Mohammad al-Hassan, a Syrian opposition activist, told the AP. "It's warplanes against Kalashnikovs, tanks fighting against rifles," he said. "I don't know how long this situation can be sustained."
The flurry of diplomatic activity in the region comes after months during which the United States has resisted pleas from some opposition leaders to join the fighting or provide weapons.
The Obama administration has said for months that further militarizing the situation would only make things worse for the Syrian people.
What's more, senior State Department officials have publicly said they are concerned about the presence of al Qaeda elements that are mixing with some rebel forces.
But one Obama administration official says the latest intelligence shows there are few "al Qaeda types" among opposition leaders and fighters. The official described the opposition as "ordinary Syrians."
A Syrian opposition source says al Qaeda is not the main force behind the Free Syrian Army, the main rebel fighting force. Rather, it is composed of Syrian citizens--and, importantly, more and more Assad military members who have defected to the opposition.
Many of those Syrian soldiers who have switched are Sunni Muslims. Assad comes from the Alawite sect of the religion.
In a boost for the Free Syrian Army, many of those Sunni defectors switched sides with their government-issued weapons in hand. Since rebel forces have been seeking arms from the United States and other nations for months, the defectors have provided much-needed firepower.
"We're taking matters into our hands," the opposition source says. "We'll finish what we started."
John T. Bennett covers national security and foreign policy for U.S. News & World Report. You can contact him at email@example.com or follow him on Twitter.