Israel stands to lose strategically if either Assad or the opposition wins decisively. The best it can hope for, however, is the survival of a weaker regime.
Israel's best hope in Syria is survival of a weaker Assad
For much of the past two years, Israel stood sphinxlike on the sidelines of Syria's civil war. Did it want Bashar Al Assad's regime to survive? Did it favour western military intervention to help opposition forces? What did it think of the increasing visibility of Islamist groups? It was difficult to guess.
In recent weeks, however, Israel has moved from relative inaction to a deepening involvement. It launched two air strikes on Syrian positions in May. At the same time, in what then looked suspiciously like an attempt to corner the US into direct intervention, it fomented claims that Damascus had used chemical weapons. Last week, based on renewed accusations, the US said it would start giving military aid directly to the opposition.
On Tuesday, Israel's prime minister, Benjamin Netanyahu, was forced to denounce as "nonsense" mounting evidence that Israeli forces have been operating secretly in Syria.
Israel's aura of inscrutability remains, nurtured by a series of leaks from Israeli officials. Their statements have tacked between threats to oust Mr Al Assad in one moment and denials in the next that Israel has any interest in his departure. Is Israel trying to sow confusion, or is it simply confused itself?
The answer can be deduced by considering the unappealing outcomes for Israel, no matter who emerges triumphant in Syria. The fact is that Israel stands to lose strategically if either the regime or the opposition wins decisively.
Mr Al Assad, and before him his father, Hafez, ensured that for decades the so-called "separation of forces" line between Syria and Israel, after the latter occupied the Golan Heights in 1967, remained the quietest of all Israel's borders.
A taste of what might happen should the regime fall was provided in 2011 when more than 1,000 Palestinians massed next to the Golan while Mr Al Assad was busy repressing demonstrations elsewhere. At least 100 Palestinians crossed into the Heights.
Last week, as fighting intensified between the rebels and the Syrian army at the town of Quneitra, next to the only crossing between Israel and Syria, UN peacekeepers from Austria began pulling out because of the danger. Opposition forces briefly captured the town.
The Quneitra fighting was a reminder that any void on the Syrian side of the border will quickly draw Palestinian militants and jihadists keen to settle scores with Israel. That point was underlined when Amir Eshel, Israel's air force commander, warned that after a regime collapse, "we could find its vast arsenal dispersed and pointed at us".
The Israeli military is reported to be considering two responses, familiar from Lebanon: invading to establish a "security zone" on the other side of the demarcation line, or covertly training and arming Syrian proxies in the same area.
Neither approach worked well in Lebanon, but there are some indications currently - despite Mr Netanyahu's denial - that Israel is already pursuing the second track.
If the future looks bleak for Israel with Mr Al Assad gone, it looks no brighter if he entrenches his rule.
A strong Al Assad means Syria continues to play a pivotal role in the alliance opposed to Israeli regional hegemony, along with Iran and Hizbollah, the Shia militia in Lebanon.
Hizbollah's formidable prowess in guerrilla warfare is the main reason Israel no longer occupies south Lebanon. Similarly, Hizbollah's arsenal of rockets pointed at Israel is a genuine deterrent, restraining greater Israeli aggression towards Lebanon, and also Syria and Iran.
Israel's air strikes in early May appear to have targeted shipments through Syria of sophisticated weaponry for Hizbollah, probably supplied by Iran. Longer-range missiles and anti-aircraft systems are seen as "game-changing" by Israel because they would further limit its room for offensive operations.
Israel would be equally stymied if Mr Al Assad stays in power and upgrades his anti-aircraft defences with the S-300 system promised by Russia.
Either way, Israel's vaunted ambition to attack Iran to prevent what it claims is Tehran's goal of developing a nuclear bomb - ending Israel's monopoly on such weapons in the Middle East - would probably have to be shelved.
But if neither Mr Al Assad's survival nor his departure is appealing, what would be in Israel's interests?
According to some well-placed commentators, the best Israel can hope for is that Mr Al Assad holds on - but only just. That would keep the regime in place, or boxed into its heartland, but sapped of the energy to concern itself with matters other than immediate survival. It would be unable to offer help to Hizbollah, isolating that party's militia in Lebanon and cutting its supply route from Iran.
Analyst Ben Caspit has noted further that in closed-door discussions the Israeli army favours an "optimal scenario" of Syria breaking into three states, with Mr Al Assad confined to an Alawite canton in Damascus and along the coast.
A long war of attrition would have additional benefits for Israel, following the decision by Hizbollah's leader, Hassan Nasrallah, to draft thousands of fighters to assist the Syrian army. Big losses could deplete Hizbollah's ranks and morale, while fighting is likely to spill over from Syria into Lebanon, tying up Hizbollah on a second front.
But there is a risk here too. If Hizbollah performs well, as it did in defeating the rebels last week at the town of Qusayr, its position in Lebanon could be strengthened rather than weakened. And in that situation Mr Al Assad's debt to Hizbollah would only deepen.
Such calculations are doubtless exercising Israeli military minds. The greatest danger of all is that should Israel decide to increase its interference in Syria, yet more parties would likely be drawn in, turning the conflict into a regional one. The question is whether Israel might see that as advantageous.
The Israeli sphinx isn't offering answers quite yet.
Jonathan Cook is an independent journalist based in Nazareth