Many outside of Syria may consider that man to be the country's president, Bashar al-Assad - the autocratic leader currently facing an unprecedented popular uprising against his rule.
Others, however, especially those with intimate knowledge of the inner workings of the Syrian hierarchy, believe that the man who holds the key to Syria's future is the president's brother: Maher al-Assad.
The Syrian Army's elite Fourth Division and the country's Republican Guard, both under the control of Maher al-Assad, are currently engaged in a concerted effort to crush the uprising which sparked to life in the southern city of Dara'a but is now burning fiercest in towns and villages throughout the north-western Idlib Province.
It is the reputation of the man leading them as much as the weaponry itself which has sent an estimated 10,500 men, women and children fleeing in terror across the Turkish border and into the surrounding mountains.
"Maher is spoken of as tough, mean or cruel depending on who you talk to," Former US Ambassador to Syria Richard Murphy told Deutsche Welle. "He is seen as the 'enforcer' for the regime, the one who oversees the dirty work of the regime."
"Little is known about Maher the person outside of his small circle of family and friends," Former Canadian Ambassador to Syria Brian Davis told Deutsche Welle. "It is said that he is ruthless, hard line, decisive and willing to use whatever force is necessary to achieve his goals. That said, there seems to be more anecdotal evidence to support that analysis than proven facts."
Majd Jadaan was once part of that small circle of family and friends. As the sister of Maher's wife, Manal, Jadaan was close to the al-Assads until she fled the current crackdown for a life as a dissident in the United States.
"Maher is a very shy and reticent person but he takes in everything you say and understands it completely, analyzing it; he may not be very well educated but he is very intelligent," she told Deutsche Welle. "He is a very complex character; insular with few friends, mysterious and scary; very stubborn and bad-tempered yet a good father to his two daughters."
"In contrast, his reputation with the Syrian people is very clear and it comes from his record of brutality," she added. "People say they have seen him killing civilians by his own hands and I believe this."
This reputation has been enhanced in the last few weeks after a video purportedly showing Maher firing his weapon indiscriminately into a crowd of unarmed protestors was leaked onto the Internet. It is not clear in the film who the man is but Maher's notoriety is such that many Syrians believe it is the president's brother indulging in his infamous bloodlust.
Head of security forces
As well as heading the armored Fourth Division and the Republican Guard, Maher also has great influence over Syria's feared intelligence service. It is said that Maher has built the forces at his command in his own image.
Unlike many of the other areas of the Syrian military which are made up of conscripts, Maher's forces are professional and elite troops which are unlikely to defect or hesitate to carry out his orders - even when these include the killing of unarmed civilians.
Together, the three unswervingly loyal bodies under Maher's influence form the main pillars of the Syrian security apparatus.
"As commander of the Republican Guard which protects the president and the regime, Maher is in a position to apply considerable pressure on Bashar should he feel strongly that his own views should win out," said Ambassador Murphy.
Such a position is believed by many to wield more power and influence than the presidency itself. Rather than being second-in-command to his older brother, it is alleged by some that Maher is in fact the man in charge.
Jadaan revealed that Maher wields as much power as the president and that the two brothers share the same goals: to oppress the people of Syria, to keep the country under the control of the al-Assads and to make sure that nobody questions what they do and how they do it.
"Bashar is portrayed as the dignified leader, while Maher is regarded as the enforcer but all this killing and torturing is not new to either of them," she said. "Believe me, Bashar is just as brutal as Maher."
Analysts say that the structure of the modern Syria mirrors that of the previous regime of Bashar and Maher's father, Hafez al-Assad - the man who groomed his sons in their respective roles. Hafez ruled in the image of a statesman while his younger brother Rifaat was the one getting his hands dirty. It was Rifaat who personally conducted the 1982 Hama massacre in which some 10,000 Sunni Muslims were killed.
"The brothers have been raised in the same school of dictatorship as their father," Majd Jadaan said. "This good angel-bad angel game was played out by their father and uncle who also divided up the country between them. Now Bashar handles the political and diplomatic part, playing the innocent guy, while Maher does the killing."
Jadaan rejects the president's claim that the al-Assad regime is being targeted by extremists and that Syrian society is being undermined by foreign "saboteurs."
"There are no armed gangs or external meddling," she said. "No-one can smuggle a pack of cigarettes into Syria without the al-Assads knowing. This is all happening because the most important matter to them is staying in power - no matter how many people are killed. It was the same with the father and now the same with the sons."
With the 1982 Hama massacre ordered to neutralize an uprising against the al-Assad family, the similarities to events unfolding in Idlib Province under Maher's command will not be lost on those running for their lives.
Losing control of the region would have been a bitter blow to the al-Assads. The unleashing of Maher and his forces by his brother Bashar is an ominous sign that the modern incarnation of the regime will also stop at nothing to protect its 41-year reign.
Author: Nick Amies
Editor: Rob Mudge