A major offensive against the Syrian army is under way in the south of the country, the fighting extending right up to the frontier with Israel.
The immediate goal of the rebels seems to be the crossing point between the Israeli-occupied Golan Heights and Syrian-controlled territory at Quneitra, and the roads leading to the town itself.
Accordingly Israel has declared the area along the frontier a closed military zone and is watching developments there closely.
Over recent months, Syrian government forces appear to have made some significant gains to the north and west of Damascus.
But some Israeli analysts see the fighting to the south as potentially having a key impact upon the wider dynamics of the Syrian crisis.
"For the past two months the Syrian army has suffered major setbacks in the southern sector," the veteran Israeli strategic commentator Ehud Yaari told the BBC.
"I have always believed that the key to the conflict would be in the southern sector and it's beginning to tilt that way.
"The way the Syrian army and its allies like Hezbollah are deployed means that there is an opening in the south."
The capture of Quneitra, Mr Yaari argues, would be a symbolic prize - but he clearly believes that the south could be the launch-pad for a rebel thrust against the Syrian capital.
At this stage the rebels do not have sufficient forces for such an operation.
But locally, Mr Yaari says, they are making significant headway against the two Syrian army brigades - the 61st and the 91st - that are deployed in the area.
"In recent weeks", he explains, "the rebels have scored some significant successes, capturing the villages of Qahtania and the high ground of Tal al-Ahmar. Jaba has been captured further south.
"Basically, the rebels have broken the defensive system of the Syrian forces in the area, which is relying upon heavy artillery fire in response."
The battle can be watched from the Israeli frontier.
The Syrian government claims that there is some kind of co-operation between Israel and the rebels, not least because the area is now largely in rebel hands.
Mr Yaari suggests that given the significant and efficient handling of casualties - some 800 Syrians, many of them rebels - by Israeli hospitals, along with humanitarian assistance given to villages across the frontier, "it would not be wrong to assume some kind of contact between the Israel Defense Forces and certain rebel groups".
So how is the fighting viewed in Israel?
The official position is that it does not seek to interfere in the Syrian fighting but will respond (as it has swiftly in the past) if there is any leakage of fire onto Israeli territory.
Mr Yaari believes that, in general, Israelis would like to see the demise of Bashar al-Assad.
He accepts that the rebel coalition contains Islamist groups who are no friends of Israel. But as he puts it, many Israelis reluctantly take the view that "the devil we don't know may be better than the devil we do".
This Mr Yaari explains by saying that the Assad regime is seen in Israel as a key link between Iran and Hezbollah in Lebanon.
"If President Assad falls, Hezbollah effectively becomes locked in southern Lebanon and this would produce a very different strategic situation," he adds.