|The answer is in the Masonic Handshake|
The main reason for the heightened tensions on the northern front is Iran and Syria's interest to intensify and hasten the arming of Hezbollah. Tehran apparently believes the West's patience is running out quickly and that by the end of the first half of 2013, or by the end of the year, Washington or Jerusalem – or both – will decide on a military strike against Iran's nuclear facilities.
The Iranians want to deter Israel and the Western nations from making such a decision by threats of mass casualties and devastation in the Israeli home front. Tehran plans to realize this threat with the use of Hezbollah and Syria's huge missile and rocket arsenal. Particularly important for the Iranians is Hezbollah's arsenal, which is protected from a ground invasion and is deployed in the heart of a supportive population in south Lebanon.
While Syria has a far larger amount of rockets and missiles, it is difficult to gauge how many of them will actually work when Iran will need them most. Therefore, Iran is looking to beef up Hezbollah's arsenal with as many accurate and devastating advanced long-term rockets as possible - rockets such as the Fateh-110, which are capable of reaching the Tel Aviv metropolitan area and even further south.
A significant amount of such rockets would allow Hezbollah to fire a relatively large number of them simultaneously. Assad does not possess any spare rockets or missiles to give Hezbollah so it may threaten Israel's cities. The Assad regime needs its missiles in the fight against Syrian citizens who are assisting the rebels.
However, Hezbollah would very much like to get its hands on Assad's Yakhont anti-ship cruise missiles, which pose a major threat to Israeli Navy vessels and gas fields located up to 300 kilometers (186 miles) from the coast. According to the New York Times, Russia has apparently transferred to Syria recently an improved version of the missile, outfitted with an advanced guidance system that makes them more accurate than the older version.
Assad also has an interest in supplying Hezbollah with advanced, mobile anti-aircraft missile batteries that can protect the Lebanese Shiite group's surface-to-surface missiles and cause heavy casualties to the Israeli Air Force that will try to take them out.
Therefore, Iran and Syria currently have a common goal: Bolster Hezbollah's rocket and missile arsenal while making it more resilient to Israeli airstrikes.
Israel apparently has no intention of allowing Khamenei and Assad to intensify the threat already posed to the Israeli home front, and it does not plan on allowing Hezbollah to diminish the IDF's ability to quickly neutralize this threat if needed.
This "red line," it has been reported, has been implemented by Israel three times as of late – when it bombed a convoy en route to Lebanon and when it attacked missiles stored in Syrian warehouses ahead of their transfer to Hezbollah in Lebanon. Syria, Iran and Hezbollah each had its own reasons not to respond to these attacks in the short term.
The question is – what will happen next time? Assad has apparently not given up on his plan to supply Hezbollah with "deterrence diminishing" weapons as a reward for the Shiite group's assistance in his regime's battle for survival. Assad also wants Hezbollah to safeguard his strategic weapons systems so they will not fall into rebel hands.
This is why the West estimates Israel will apparently be forced to attack - perhaps in the near future - additional arms shipments making their way from Iran to Hezbollah via Syria. It is also estimated that Assad would have to respond, despite the fact that he has almost no effective retaliation options. The Syrian army, in its current state, cannot attack us on the ground, and if it fires missiles toward Israel's home front, Israel will destroy most of the Assad regime's military assets, and other assets, which are crucial for its continued survival.
Therefore, Assad will try to attack Israel indirectly in a way that will not draw a harsh Israeli response. One possibility is a terror attack against an Israeli target abroad. However, the preparations for such an attack, with the cooperation of Iran's Revolutionary Guard and Hezbollah's special unit, may take a long time.
In addition, such an attack would most likely be thwarted by Israeli intelligence. In any case, the effect of such a Syrian response would not be worth the effort. The other, more effective option is to shatter the calm that has prevailed in the Golan Heights for the past 40 years.
Assad, Khamenei and Nasrallah have apparently reached the conclusion that the Golan Heights is the soft spot which can be used to effectively deter Israel from thwarting arms transfers to Hezbollah. Syria, Iran and Hezbollah have issued numerous threats clarifying that the response to additional Israeli strikes will be "strategic…in the Golan." The bottom line: Assad will allow Hezbollah to operate in the Golan, and should Israel attack the transfer of "deterrence diminishing" weapons in Syria or Lebanon, the lives of Israelis in the Golan will be similar to the lives of Israelis residing in communities bordering the Gaza Strip.
Israel will not be able to respond with full force because the terror attack may not be on a large enough scale to justify confining Israel's citizens to shelters for a period of a few weeks or because the identity of those who carry it out will not be clear. This would make it difficult for Israel to garner international support for a forceful military response.
Assad and Hezbollah's threat on the Golan Heights puts the ball back in the Israeli court and makes the dilemma all the more difficult: How will Israel respond the next time a shipment of advanced weapons makes its way from Syria to Lebanon? For now, Jerusalem (which is coordinating its strategy with Washington) is not blinking.
To make Israel's intentions clear, a senior official told the New York Times Israel does not plan on intervening in favor of the rebels, but it will not allow Syria and Iran to transfer "game-changing" weapons to Hezbollah.
The Israeli official stressed that any Syrian retaliation to an Israeli attack will cause Israel to topple Assad's regime. How? By attacking what is left of his army and other assets that allow for the Alawite regime's continued survival. More importantly, Israel will destroy the assets the regime plans to use in order to create an Alawite enclave that will be connected to the Hezbollah-controlled Bekaa Valley in Lebanon.
Such an enclave in the Mediterranean Basin is crucial not only for Assad and his sect, but also for the Iranians and the Russians, who want to preserve their interests in Syria. An Alawite enclave would serve this purpose well, and this is why the Iranians are setting up an international Shiite force that will fight alongside the Alawites in the enclave and outside of it and also help Assad maintain control over Damascus. The Russians, for their part, wish to hold on to facilities in the port of Tartus, which is situated at the center of the future Alawite enclave.
Israel made it clear to Assad and his patrons that any attacks in the Golan will dash their hopes of creating a coastal sanctuary in the Alawite enclave.
The Russians are reading the map well and are aware that in the current situation Assad does not have the means to deter Israel from attacking Hezbollah-bound arms convoys. This is why Putin's aides – in order to deter Israel and the Americans from attacking in Syria - leaked to the press that Moscow will finally transfer to Syria three S-300 missile batteries. The original agreement for the transfer of long-range (200 kilometers, or 124 miles) missiles was signed some three years ago –before the revolt against Assad erupted. Russia has already received some of the payments, but the missiles have not been transferred to Syria due to American and Israeli pressure on the Kremlin not to supply the Assad regime with these missiles, as they may fall into Hezbollah's hands and undermine regional balance - because the Israeli Air Force would be forced to act in Lebanon before these missiles hinder its ability to operate there.
Medvedev, the Russian president at the time, was convinced, and he decided to freeze the agreement in 2010, but he did not cancel it. Nothing has changed since then, but Putin wants to use this arms deal to force Netanyahu to guarantee that Israel will not attack Syria and threaten the regime there. The Russian president apparently wants a similar commitment from Obama. It is safe to assume that Netanyahu did not give such a guarantee to Putin when the two met on the eve of the Shavuot holiday in Sochi. This is why Putin is refusing to promise that he will not transfer the advanced missiles to Syria. This impasse led to the vague statements made by Foreign Minister Lavrov and Putin's spokesman Peskov, from which we can understand that Russia plans to transfer the S-300 missiles to Syria, despite the fact that the two senior officials did not specifically say so. Based on Russia's conduct in recent years, it may very well delay the arms transfer.
The Russians certainly do not want to see their rockets fall into the hands of Islamist Syria rebels or force Israel to attack and destroy the missiles in order to restore its freedom to operate in Lebanese and Syrian airspace.
This issue was discussed during the meeting between Defense Minister Moshe Ya'alon and CIA director John Brennan, who made a surprise visit to Israel. The two also discussed Iran.
In the meantime, it is safe to assume that Syria and Hezbollah will not rush to act against Israel in the Golan or along the Lebanese border, mainly because Iran has an interest in keeping Hezbollah and Syria's rocket and missile arsenals ready for action in order to deter Israel and the US from attacking its nuclear facilities. This interest will remain relevant for at least another six months, perhaps even more. Therefore, Iran will advise Assad to act with restraint, for now, even if Israel strikes Hezbollah-bound arms convoys.