The man threatening the status quo in one of the world's most politically entrenched regions is not the sort of person given to grandiose gestures or impassioned oratory.
Compact, neat and precise, 73-year-old former Syrian Vice President Abdul Halim Khaddam has the quiet assurance of a man who has spent three decades in one of the Middle East's most formidable power circles.
But it's the content of his statements these days that's shaking international circles.
"President Bashar al-Assad's policy is built on personal interest for him and his family," he said, referring to the current Syrian leader during an interview with ABCNEWS.com at his luxurious Paris residence.
"All the decisions he has taken on, internal and external issues, have put Syrians in a corner, and the country is in a very dangerous situation," he added. "My role now is to finish the bad situation for the Syrian people right now and get rid of the regime."
Delivered dispassionately in his Paris living room more than 18 months after his resignation, Khaddam's quiet resolve seems far removed from the intrigues of Syrian politics.
But it's a dramatic break from his former boss in the Syrian capital of Damascus. This, after all, is the seasoned statesman who signed vital decrees enabling the young, inexperienced Assad to take over the presidency after the sudden death of his father, Hafez al-Assad, in 2000.
Even more explosive are his recent public insinuations that Bashar al-Assad played a role in the assassination of former Lebanese Prime Minister Rafik Hariri.
Months after a U.N. investigator's report cited witness testimony that Assad had personally threatened Hariri before his killing, Khaddam is publicly implicating the Syrian president in the assassination.
Syria has consistently denied any involvement in Hariri's killing. But Khaddam's accusations have been the most serious blow to Assad, coming from one of his most senior officials.
Indeed Khaddam's latest salvo is just one shot -- albeit an extraordinarily powerful -- in a fusillade against the regime.
Alienated from the international community -- including former ally Saudi Arabia -- and facing mounting U.S. criticism over its alleged role in the Iraq insurgency, the once-solid Damascus regime is starting to display potentially fatal cracks.
One crucial result of Khaddam's denouncement of the Damascus regime is its impact on the Syrian opposition at home and abroad.
Given the regime's tight control of the media and its authoritarian crackdowns on the opposition inside Syria, it's difficult to conclusively assess the effects of Khaddam's falling-out inside the country.
But outside the Baathist-controlled country, there's little doubt that it has bolstered the Syrian opposition in exile.
"It certainly boosts the self-confidence of the opposition to realize the major rats are deserting the sinking ship," said Volker Perthes, director of the Berlin-based German Institute for International and Security Affairs.
"Judging from the nervous reaction by the [Syrian] regime, it shows Khaddam has touched a weak spot. And what weakens the regime, strengthens the opposition," he added.
In European capitals such as Paris and London -- long the centers of Syrian opposition in exile -- political analysts say there has been a frenzy of meetings, alliances and alignments between a diverse range of opposition figures in recent months.
One of Syria's most respected secular opposition figures, Riad al-Turk, a veteran leftist leader who has spent more than 20 years of his life in Syrian jails, is currently traveling in Europe, fueling rumors of a new opposition nexus-in-the-making.
Last year, in what was widely seen as an effort to adjust its image, his Syrian Communist Party changed its name to the Syrian Democratic People's Party.
Indeed, across the ideological spectrum, the often fractious Syrian opposition groups have been revamping their programs, sprucing their rhetoric, and bridging once-formidable gaps.
Analysts note, for instance, that over the last few years, the Syrian wing of the Muslim Brotherhood based in London has considerably moderated its political and ideological positions.
Banned in Syria under Law 49 of 1980, which condemns any member of the Muslim Brotherhood to death, the global Islamic organization is believed to have widespread support and grass-roots links inside Syria.
According to Joseph Bahout of the Institut d'Etudes Politique de Paris, the Muslim Brotherhood's recent moderation has enabled it to make connections with secular opposition figures in Europe.
"The liberals and leftists have been making links to the [Muslim] Brotherhood because the Brotherhood has become much more flexible, intellectual, and much less dogmatic," he said. "They are no more the frightening Islamists."
The group's armed uprising in 1982 led to a brutal crackdown by the Syrian Army, but Muslim Brotherhood officials say the organization has been rejecting violence.
"The Muslim Brotherhood in Syria adopts dialogue with all political parties and is ready to cooperate with all groups and individuals -- including Khaddam -- to achieve peaceful democratic reform in Syria," said Ali Sadreddin al-Bayanouni, London-based leader of the Syrian Muslim Brotherhood, in an e-mail interview with ABCNEWS.com.
Last year, a number of parties with often conflicting ideologies attended a conference in Paris aimed at coalescing the Syrian opposition.
It was followed by the "Damascus Declaration," a joint statement calling for peaceful regime change by opposition figures in the Syrian capital.
But analysts warn that beneath the united front, there are potentially divisive problems of conflicting agendas as well as controversial past records and alliances.
Rifaat al-Assad, Hafez's long-alienated brother based in Marabella, Spain, for instance, is considered too close to the Alawites, a minority Muslim sect that has held power for more than four decades in the Sunni majority country.
Also, as the commander of the Syrian internal security forces during the 1982 Hama massacre, Rifaat is considered an unsavory political figure.
And if the Damascus regime were to fall, separatist Syrian Kurdish groups would likely be at odds with the majority Sunni groups such as the Muslim Brotherhood on the critical issue of national stability.
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.