Is Israel Hastening the Fall of Assad?

Israel’s official silence following its airstrikes on weapons depots in Syria earlier this month fueled accusations in every direction. Damascus condemned it as an attempt to destroy the regime, Tehran said the real targets were Iran and Hezbollah, analysts in the U.S. said it was a demonstration of “credibility.”
But now a Syrian rebel commander has a different take: “The assault was in support of Assad.”

Abdul Qader Saleh, commander of the Al-Tawhid Brigade, told the Turkish news agency Cihan that Bashar Assad’s regime has in fact already been defeated and that Iran and Hezbollah , with Israel’s backing, are preventing his downfall.
“The Syrian opposition was on the verge of taking over Assad’s weapons caches and that is why Israel attacked Syria,” Saleh claimed.
“There were several senior Syrian officers who were planning to defect and hand over weapons to the opposition. Israel bombed those caches for fear they would fall to the hands of the opposition. They contained air defense systems and heavy artillery. The assault was in support of Assad.”

This clashes with analyses that claim Israel aims to overthrow Assad in order to get to Iran. The claim is about as credible as the rest of the assertions of Israel’s intent. But Saleh’s accusation isn’t out of nowhere.
Efraim Halevy, who served as chief of the Mossad from 1998 to 2002, argued the same in a piece in Foreign Affairs:

Israel’s most significant strategic goal with respect to Syria has always been a stable peace, and that is not something that the current civil war has changed. Israel will intervene in Syria when it deems it necessary; last week’s attacks testify to that resolve. But it is no accident that those strikes were focused solely on the destruction of weapons depots, and that Israel has given no indication of wanting to intervene any further. Jerusalem, ultimately, has little interest in actively hastening the fall of Bashar al-Assad.
Israel knows one important thing about the Assads: for the past 40 years, they have managed to preserve some form of calm along the border.

If you compare the threat assessment Israel must be doing on Assad with the threat assessment Israel must be doing on Sunni rebel extremists possibly coming to power in Syria, clearly the latter is significantly worse. Israeli foreign policy is menacing and criminal, but it isn’t stupid.
Not only does Israel in all likelihood see Assad as less threatening than al-Qaeda-affiliated militias, but there is also an argument out there, made yesterday by Thanassis Cambanis in Foreign Policy, that Iran’s backing of Assad is draining the Islamic Republic’s resources and reputation in the region. Israeli policymakers may be viewing that favorably.