Analysts also warn that the U.S. experience in Iraq is adversely affecting U.S.-based Syrian exiles considered too close to Washington neoconservative circles.
This includes Farid Ghadry, Washington-based president of the Reform Party of Syria.
"Ghadry wants to be the Chalabi of Syria," said Perthes, referring to Iraqi exile Ahmed Chalabi's use of the United States to bring regime change in Iraq. "Chalabi is a role model for Ghadry."
But it's the very role model that makes Ghadry a suspicious opposition figure for his European and Islamic counterparts. Given what is widely seen in the Middle East and Europe as the U.S. debacle in Iraq, opposition figures -- including Khaddam -- are at pains to stress their distance from Washington.
The critical issue, though, is whether Syrian opposition groups in exile can bring about change in a tightly controlled state that routinely cracks down on political dissent.
It's a complex question, and the answers are often contradictory.
"I would tend to say no," said Perthes of the Berlin group. "You cannot change that country from Marabella, Paris, London or Vienna, [Austria]. Once you're out of the country, you're out of the game."
Bahout in Paris maintains that the critical challenge for the opposition abroad is to find links with "the architecture of the regime" such as the army, the security apparatus, as well as community and tribal groups. "If they don't forge links, the opposition in exile will remain a virus that the regime in Damascus can live with."
While some opposition figures, such as the Muslim Brotherhood's al-Bayanouni, stress their links inside Syria, others prefer to hold their cards close to their chests.
Sitting under the gaze of a majestic painting of a medieval torture scene in his Paris salon, Abdul Halim Khaddam is deftly deflecting questions about his political ambitions and alliances.
"It's not important to me where my position will be in a future Syria," he said. "What's important is the Syrian people and what the Syrian people want."
What he's sure of, though, is that one day he will return to Syria. "My country is in my heart although my body is outside," he said. "I am very confident that I will return home." In what position, though, he's not willing to say.