Saudi Arabia has taken up coordination of Arab support for the Syrian uprising at the expense of its fellow Gulf Cooperation Council member state Qatar, Reuters reported on Friday.

While governments in neither Gulf kingdom would officially confirm the shift, several senior sources in the region told the news agency that Saudi Arabia prevailed over its small neighbor to decide which of the groups that are battling the regime of President Bashar Assad in Syria get their support. The division between a Qatari sphere of influence on the northern border with Turkey and a Saudi sphere on the southern, Jordanian frontier is over.

Prince Salman bin Sultan, a senior Saudi security official, is now running relations with the Syrian rebels, backed by his elder brother, intelligence chief Prince Bandar bin Sultan, Saudi Arabia’s former ambassador to the United States.

Describing the shift in military supervision, several sources from the political and military leadership of the Syrian opposition and a Saudi source said that anyone, whether a state or among wealthy Arabs who have been making private donations to the rebel cause, would now need the Saudi princes’ approval over what is supplied to whom if they wish to send arms into Syria.

The monarchies share sectarian and strategic interests in hastening Assad’s demise. He is the only Arab ally of their regional nemesis Iran. Replacing his government with a majority Sunni regime would weaken the Shia axis in the Middle East and limit Iran’s retaliatory options in case there is an American or Israeli attack on its nuclear sites which both Arab and Western powers suspect are part of a weapons program.

Unlike their American allies, who are apprehensive about arming a radicalized Islamist insurgency, Saudi Arabia and Qatar have provided weapons to fellow Sunni Muslims in Syria who compromise some 70 percent of the population and form the backbone of the rebellion against the minority Alawite regime in Damascus.

But they have sent money and weapons to different groups. Qatar’s support for the Muslim Brotherhood in particular is viewed with suspicion in Riyadh and Washington. The Islamist organization has risen to prominence across the Middle East and North Africa in the wake of “Arab Spring” uprisings in 2011. Its advocacy of political Islam does not conform to Saudi Arabia’s puritanical strain of the religion, Wahhabism, nor the largely apolitical Salafist movement is prefers to support.

The Muslim Brotherhood also favors republicanism and the use of populist tactics to gather democratic support, an affront to Saudi Arabia’s authoritarian monarchy.

Despite a temporary alliance between Egypt’s Muslim Brotherhood and the Saudi government through the 1960s and 1980s to counter Egyptian president Gamal Abdel Nasser’s secular Arab nationalism, growing religious dissent in the kingdom, especially after the Gulf War in 1991, and the rising threat of Islamic terrorism alerted the Saudis to the dangers of political Islam. They similarly regard Turkey’s form of Islamism warily, even if it is informed by more tolerant Sufi culture and Kemalist secular traditions.

Qatar doesn’t share the Saudis’ concerns. Unlike its neighboring kingdom, which houses a Shiite majority in its oil rich Eastern Province, Qatar’s population is largely homogenous and the royal family is popular, allowing the emirate to conduct an activist foreign policy, whether through its Al Jazeera television channel or by deploying fighter jets over the skies over Libya as did in 2011 in concert with Western allies.