Since the outbreak of civil war in Syria in 2011, Israeli officials have observed events to the north with caution and concern. The concern has derived from the presence of anti-Israel paramilitary and terrorist elements on both sides of the fighting lines in Syria.The caution, meanwhile, relates to the very deep aversion felt in the Israeli system toward the possibility of the Jewish state being sucked into the morass of the Syrian war. Israel’s Lebanon experience has left a deep institutional memory warning against overly ambitious incursions into the affairs of neighboring states.Nevertheless, evidence is emerging of an increasing, though still modest Israeli involvement in events beyond the separation of forces line on the Golan Heights.The least ambiguous evidence of Israeli activity related to Syria is the series of air raids against weapons convoys headed for Lebanon. These have been attributed by foreign media to Israel, and were carried out to prevent the transfer of certain weapons systems from Syria to Hezbollah.However, the latest emerging indications relate not to activity deep within the skies above Syria. It can not be ruled out that the contacts in question are happening, discreetly, very close to the ground – and very close to the border.Israeli officials have observed with concern the recent ebb and flow of the fighting in the Deraa and Quneitra provinces in southern Syria. The rebel fighters in this area, as elsewhere, are a varied and disparate group. The southern front is the focus of the limited Western and Arab support offered the rebels.A Western command center at which US, Jordanian, Saudi, British and French personnel are present has been established to coordinate aid to the rebels in the south.But the “moderate” rebels of the Supreme Military Command and the related Syrian Revolutionaries Front, who benefit from the modest flow of Western and Saudi aid, are not the only groups fighting President Bashar Assad in the south.Jabhat al-Nusra, the official Syrian franchise of al-Qaida, is also playing a major role in the fighting in the south. The Salafi Ahrar al-Sham group is also present in force among the southern rebels.These groups operate in coordination with the Western-supported fighters.In recent weeks, forces led by Jabhat al-Nusra have made major territorial advances. In late April, these forces captured eastern Tel al-Ahmar (the Red Hill), situated 5 km. from the Israeli border on the Golan Heights. Western Tel al-Ahmar, which is just 2 km. from the first Israeli positions, was captured earlier in the month.Rebel forces hope to push on to Quneitra itself. Their intention is to establish a contiguous strip of rebel-controlled territory in across western Deraa and Quneitra provinces – just 100 km. southwest of Damascus.For Israel, the possibility that al-Qaida-linked jihadis could establish themselves along one of its borderlines represents a nightmare scenario. In a video released after the capture of the hill, a Nusra spokesman was heard to praise Osama bin Laden as the “Lion of Islam,” and to vow continued war on “Jews and crusaders.”So the problem is clear. What is Israel doing to respond to it? In addition to increasing drone surveillance and intelligence gathering across the border, the evidence suggests that Israel has established contact with non-jihadi, Western-supported rebel elements, with the intention of ensuring the jihadis are prevented from establishing themselves along the cease-fire line on the Golan.The medical care that the Syrian regime charges that Israel affords to wounded Syrian fighters has served to facilitate this process. One thousand or so Syrian fighters have received it, with the more lightly wounded being treated at the IDF field hospital established close to the border, and others in hospitals in northern Israel.Col. Abdullah al-Bashir, who commands the Supreme Military Council, a prominent Western- backed rebel element, was among the military personnel to be treated in Israel.In addition to direct contact with the rebels, Israel is also in contact with local leaders across the border, with the intention of offering them inducements to refuse shelter and medical care to the jihadi fighters.Alleged Israeli support for Western-backed rebels in this arena is made yet more necessary by the fact that defeat for the rebellion in Deraa and Quneitra runs the risk of bringing not the status quo ante bellum, but rather Hezbollah, to the border.Fighters from the Shi’ite Islamist movement are present among pro-regime forces battling in the south. In early March, IDF troops fired at what they said was a Hezbollah team trying to place a bomb in the border area.So is the southern border coming to resemble south Lebanon in the 1980s? Is Israel being sucked into another commitment across a northern border? Precisely because the lesson of Lebanon is so deeply etched on the collective memory of the Israeli system, it is likely that the Israeli footprint in southern Syria will remain discernible, but light.There are no ideal options. Nusra, according to one source, is stronger than it appears, since it has allowed pro-Western forces to take credit for a number of operations. It does this so as to keep Western support flowing into the area, from which Nusra itself will then benefit. So any strengthening of the rebels in the south carries with it the risk of assisting precisely the enemy that it is supposed to thwart.But the alternative of passive acquiescence to either al-Qaida or Hezbollah assembling along the border is probably worse.A complicated political and military ecosystem has emerged in southern Syria, just across the cease-fire line in the Golan Heights. Israel will do its best to preserve its vital interests, while avoiding an overt presence in this arena. Maintaining the balance is not simple.As of now, it may be said that Israel is actively, if discreetly, engaged in southern Syria.