Riyadh also wants to foment an Iraq-style "Sunni Awakening" to unite Syria's majority sect to topple the minority Damascus regime of President Bashar Assad.
Middle East analyst Michael Weiss, writing in the Beirut Web portal Now Lebanon, observed Riyadh has "taken substantive measures to circumvent Washington altogether on Syria by activating a cadre of new clients in the form of a hard-line Salafist rebels who are now united under the umbrella of the army of Islam. ...
"The Saudis have enlisted '50 brigades' and some thousands of fighters under a new structure headed by Zahren Alloush, head of Liwa al-Islam, the new group's most powerful Salafist brigade."
Alloush studied Islamic theology in Saudi Arabia where his father Abdallah is a Salafist cleric.
The Saudi move is also a response to last week's formation of a hard-line Islamist alliance of 13 groups, including the powerful Jabhat al-Nusra, allied with al-Qaida, and to isolate the jihadists who're proving to be the most effective anti-regime force in Syria.
The plan seems to be to buy control of disaffected rebel bands, many of them without strong leadership, and to forge them into a well-armed force capable of battering Assad's regime.
"For us in Saudi Arabia, the worst scenario is to let Bashar survive this: he has to go," said Jamal Khashoggi, a Saudi analyst close to Riyadh's power elite.
"The world can ignore what's happening in Syria, but this is on our doorstep and it's on fire with sectarian flames that will reach all neighboring countries."
The Saudi strategy has been engineered in large part by Prince Bandar bin Sultan, head of the General Intelligence Directorate, and his brother Prince Salman, named deputy defense minister by Abdullah in August.
Bandar, Abdullah's nephew, was ambassador to the United States for 22 years (1983-2005).
He's a master of Middle Eastern intrigue and played a key role in several covert operations with the Americans, including arming Islamist mujahedin against the invading Soviets in Afghanistan throughout the 1980s.
On July 31, Bandar flew secretly to Moscow for closed-door talks with Russian President Vladimir Putin, Assad's ally, at his suburban home in hopes of persuading him to back off keeping the Syrian dictator in power.
Bandar reportedly offered to buy Russian arms worth $15 billion and not to oppose Russia's natural gas deals, but apparently to no avail.
Nonetheless, the episode underlined how Riyadh's strategic view is swinging increasingly eastward.
Bandar is Abdullah's point man on the complex Syrian imbroglio, which the Sunni Saudi monarchy sees as part of its increasingly fraught confrontation with Shiite Iran's drive to be the paramount power in the Persian Gulf and to extend its influence through Iraq and Syria to the largely Sunni Levant.
Before moving to rally the disparate Syrian rebels by showering them with petrodollars, Bandar and cohorts first eliminated rival Qatar which was funding and arming Islamist hardliners in Syria.
Gulf sources say the surprise June 25 abdication of Qatar's emir, Sheik Hamad, in favor of his son, Sheik Tamin bin Hamad al-Thani, took place with a little help from Riyadh to curb Doha's political clout in the region.
All this has meant a sharp shift by Riyadh away from the strategic alliance with the United States, established in 1945 when Franklin D. Roosevelt met King Abdelaziz ibn Saud, Abdullah's father, aboard the U.S. Navy cruiser Quincy in the the Suez Canal.
This shift has been building for some time, spurred in part by the discovery of vast shale oil deposits in the United States that dwarf those of Saudi Arabia, the world's top producer.
U.S. influence in the Arab world has been waning for a decade. But the House of Saud was deeply alarmed when Obama abandoned longtime Arab ally Hosni Mubarak in Egypt during the 2011 pro-democracy uprising.
The royals fear they could be left in the lurch as well.
The chill in Riyadh-Washington relations is likely to get icier as the Saudis seek to scupper any accommodation between Obama and Iran that does not completely eliminate Tehran's nuclear program.