The fearsome IRGC was formed in the wake of the 1979 revolution by Ayatollah Khomeini, and reports directly to the supreme leader. Some of Kahlili's claims, compiled in his book "A Time to Betray" have been met with skepticism, though the Washington Post's David Ignatius confirmed at least his relationship with the CIA.
"To this day, they have bases in Syria," he says. "The fall of Assad could ruin their plans. Saudi Arabia knows this."
Iran needs Syrian access to neighboring Lebanon to continue to shape politics there, says Kahlili and other experts on the region, as well as to intimidate neighboring Israel.
The Atlantic Council's Hof refers to Syria as Iran's "logistics bridge."
"Hezbollah's missiles and rockets pointed at Israel are Iran's first line of defense: a strong deterrent as Israel thinks about attacking Iranian nuclear facilities," he says.
"Assad has been willing to subordinate Syria's national security interests to those of Iran with respect to Hezbollah," adds Hof. "Iran fears - probably justifiably - that any successor Syrian government would either bring the Hezbollah relationship back to what it was before Bashar Al Assad assumed power or eliminate the relationship altogether."
Whether as an attempt to become a hegemonic power, or simply establish security in neighboring countries, both Iran and Saudi Arabia are intent on carrying a big stick, as well as speaking loudly.
Iran's intervention in Syria may be a symbol to the world that it is a force worth fearing. It is also believed to be actively involved in citing insurrection in Bahrain, an island in the Persian Gulf immediately off Saudi Arabia's coast.
"The Saudis have a bigger tent," says former ambassador Kattouf of that country's foreign influence. Saudi Arabia has long been an ally of the U.S. and receives significant military support, including arms sales. The Iranians tried to have a bigger tent, he says. But their support for Assad has left many regional countries skeptical of their true intentions, and has isolated Iran throughout much of the Middle East.
"[Iran] has an expansive agenda," says Kahlili. "They have infiltrated Africa, set up many collaborations with African nations, and through collaboration, they export arms, narcotics and other things."
Both Iran and Saudi Arabia are trying to influence the Sunni hardliner Muslim Brotherhood in Egypt, these experts say. Kattouf adds this becomes increasingly difficult for the Saudis, who have historically been very discriminating in which Sunnis they are willing to endorse. For example, the Saudi monarchy denied native son Osama bin Laden's request in the 1990s to employ the group of fighters he had raised to combat the Russians in Afghanistan and turn their attention to striking America.
"Saudi Arabia, even for someone who follows the region, is quite honestly hard to explain in their policies," says Kattouf. "Not all Sunnis in the opposition get their blessing or their support.
"They do pick and choose who among the conservative Islamic factions in Syria, of which there are many, they will support."
Relations with the West
Saudi Arabia has grown increasingly concerned about recent Iranian overtures to the U.S., and subsequent attention from the Obama administration. Kind words leading up to the U.N. General Assembly in late September could be the first break in more than three decades of tense diplomatic relations between the two nations. Iran hopes this will lead to an easing on sanctions against its worrisome nuclear program.
"It's deeply unsettling to the Saudis," says Kattouf. "And they may be exaggerating prospects for success."
Iran's latest goodwill tour may be seen as its attempt to break in on the historic alliance with Saudi Arabia, one of the world's most significant recipients of American military resources.
The Saudis should welcome an agreement that prevents Iran from acquiring weapons banned by the U.N., he says, and they've never wanted to see the U.S. go to war with Iran.