Though the assessment was quickly disavowed by others in Prime Minister Benjamin Netanyahu's coalition government, it reflected the difficulties facing Israel and Western countries in predicting Syria's destiny and weighing intervention.
Yuval Steinitz, minister for international affairs, strategy and intelligence, was asked at a briefing with foreign journalists whether recent successes by Assad's forces against outgunned rebels might herald victory for the Syrian leader.
"I always thought that it might be the case that at the end of the day Assad, with a very strong Iranian and Hezbollah backing, might gain the upper hand," Steinitz said.
"And I think that this is possible and I thought that this is possible already a long time ago."
Steinitz, who is not a member of Israel's security cabinet but does have access to intelligence updates as well as Netanyahu's ear, said Assad's government "might not just survive but even regain territories" from the rebels.
He declined to comment further on a possible Assad victory, citing Israel's policy of not meddling publicly in Syria.
The defense and foreign ministries received Steinitz's remarks coolly.
"This is Steinitz's personal informed - or rather, misinformed - position," said one Israeli diplomat who asked not to be named.
Netanyahu spokesman Mark Regev said Steinitz was speaking for himself and that the Israeli government did not have a formal position on Assad's prospects.
In June 2011, only three months after the Syrian uprising began with peaceful protests, then-Defense Minister Ehud Barak, the lone centrist in the previous government also led by Netanyahu, forecast Assad's fall "within weeks."
Months later, after a full-fledged insurgency had developed, a senior Israeli official said Barak had been trying to "jump the gun" and encourage Assad's foes to hasten his overthrow - an outcome that Israel viewed as inevitable at the time.
Yet the current Netanyahu government appears more cautious, given the four decades of stability Assad and his father before him had maintained on the Syrian-Israeli frontline.
Israel does not want chaos there, especially as it estimates that one in 10 of the anti-Assad rebels are radical Islamists.
Government officials also say privately they have urged Western counterparts to consider any aid to Syrian rebels carefully, lest the weaponry end up being used against Israel.
Israel has allegedly carried out at least three air strikes on Syrian sites that intelligence sources described as advanced weaponry in transit to Hezbollah. Israeli forces on the occupied Golan Heights have occasionally fired in response to Syrian gunfire when troops and rebels battle near the frontlines.
Alluding to Israel's superior military might, Steinitz said: "It is in his (Assad's) interest not to provoke us so that we get involved."
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