This and reports that Russian and North Korean arms are reaching Damascus could propel Assad's leading Arab foes, the monarchies of the Persian Gulf led by Saudi Arabia, to step up clandestine shipment of arms and ammunition to Syrian rebels.
The main arms pipeline to the rebels is through northern Lebanon, a region dominated by Sunnis with close ties to their co-religionists in neighboring Syria.
They're the majority in Syria and constitute the main driving force behind the revolution that will shortly enter its 15th month with Assad's opponents dangerously divided.
On Monday, Ismail Gha'ani, a top commander in the Islamic Revolutionary Guard Corps, the Iranian's regime's Praetorian Guard, was quoted as saying in an interview with Iran's semi-official Isna news agency that, not only were Iranian forces in Syria, they were preventing Assad's forces from slaughtering civilians.
"If the Islamic Republic was not present in Syria, the massacre of people would have happened on a much larger scale," he said.
"Before our presence in Syria, too many people were killed by the opposition but with the physical and non-physical presence of the Islamic Republic, big massacres in Syria were prevented."
Isna carried the interview over the weekend but abruptly withdrew the item without explanation, apparently after it was picked up by Western news outlets -- or maybe because of Friday's massacre at Houla was blamed on Assad's regime.
The apparent admission by Gha'ani was given added weight because he's deputy commander of the elite al-Quds Force, the IRGC's clandestine arm which operates outside Iran.
This force has long operated in Lebanon with Tehran's prized Arab surrogate, Hezbollah, and waged a covert campaign against the Americans in Iraq.
The number of Revolutionary Guards deployed in Syria isn't known, although Western intelligence sources say it's considerable.
Al-Quds Force's long-elusive commander, Maj. Gen. Qassem Suleimani, is reported to have traveled secretly to Damascus in January to meet Assad and his senior commanders.
Suleimani, who masterminded al-Quds Force operations in Iraq and covert activities throughout the Persian Gulf and Lebanon, is a key figure in Iranian policymaking, particularly in security matters.
Syria's a vital component of Iran's expansionist ambitions into the Arab world, whether in the gulf or the Levant, where Tehran can carry its conflict with Israel right to its doorstep through Hezbollah in Lebanon.
Tehran seems prepared to go to almost any lengths short of all-out war with Israel or the United States to keep Syria within its orbit.
So sending someone of Suleimani's status and reputation for covert operations to Damascus would seem to underline Tehran's determination to keep Assad's minority regime in power at almost any cost.
Suleimani, a combat veteran of Iran's 1980-88 war with Iraq, took command of the al-Quds Force in the late 1990s and has become a powerful figure in the upper echelons of the Tehran regime.
Western officials say his trip to Damascus signaled an escalation in Iranian support for Assad, which for months after the revolution broke out March 15, 2011, was limited to Revolutionary Guard advisers and counterinsurgency technology.
The United States, along with its allies, would like to see regime change in Damascus and end Syria's alliance with Iran, forged in 1980 by Assad's late father, Hafez Assad.
He was feuding with Saddam Hussein at the time and saw an alliance with the infant Islamic Republic, then about 18 months old following the 1979 Islamic Revolution, as a strategic asset against the Baghdad regime.
The Americans, then, probably view the growing al-Quds Force profile in Syria and Suleimani's Machiavellian hand there as an escalation of Iran's backing for Damascus, crimping any hopes of getting rid of Assad soon.
Whether that will translate into more robust U.S. support for the Syrian rebels isn't clear.
But the changing perceptions among Israeli leaders about what's happening in Syria are instructive.
A couple of months ago Israeli Defense Minister Ehud Barak was confidently predicting Assad's imminent downfall now, senior military officers and the intelligence community expect Assad to stay in power for the foreseeable future.