Prime Minister Benjamin Netanyahu, only just back from China, was back overseas on Tuesday, meeting with President Vladimir Putin to ensure –- or more accurately to plead — that Russia refrain from sending Syria four S-300 batteries, a $900 million, long-range aerial defense system that, Israeli experts say, would change the calculus of Israeli and US involvement in Syria.

Russian Foreign Minister Sergei Lavrov struck a defiant tone in advance of the meeting. “Russia is not planning to sell,” he told reporters in Warsaw, without specifying which systems he was referring to. “Russia already sold them a long time ago. It has signed the contracts and is completing deliveries, in line with the agreed contracts, of equipment that is anti-aircraft technology.”

Russian state TV was even more explicit. “After the S-300s are put into service, a repeat of the Libyan scenario — the imposition of a no-fly zone over the country — would be extremely difficult,” the Wall Street Journal reported Vesti-24 as saying.

Russian Foreign Minister Sergey Lavrov (photo credit: AP/Alexander Zemlianichenko)

Russian Foreign Minister Sergey Lavrov (photo credit: AP/Alexander Zemlianichenko)

Israeli experts largely agree with this assessment. The S-300, which can intercept fighter jets and cruise missiles, “is the ultimate system,” said Uzi Rubin, the former head of missile defense at Israel’s Defense Ministry and a senior researcher at the Begin Sadat Center for Strategic Studies. “It covers enormous surfaces and is so potent that when the Cypriots bought the system the Turks threatened them with war because it endangered Turkish aircraft flying over Turkey.”

Nonetheless, Rubin said, it is the fact of Russia’s unstinting involvement on Bashar Assad’s behalf in Syria, more than the precise nature of that role, which dictates the course of events.

A review of Assad’s air defenses, their capacity and their performance in recent years — including after a 2007 upgrade — underlines the importance of the S-300 amid what thus far has been unwavering Russian support.

In 1967 Israel destroyed Syria’s air force on the first day of the war. By 1973’s Yom Kippur War the situation had changed. The Russian SA-6 system downed more than 20 IAF planes over Syria.

Yet air defense systems, Rubin explained, are a lot like locks. Some are old and feeble. They can be cut with a pair of pliers and tossed aside. Some are familiar. An experienced thief knows how to extract the combination with relative ease. And some are state-of-the-art and keep all but the best at bay.

By 1982, Israel, unbeknownst to Syria, had cracked the combination to Russian air defense. On June 9, the fourth day of the Lebanon War, after Syria had moved 19 SA-6 surface-to-air missile batteries southwest into Lebanon’s Bekaa Valley in order to protect PLO forces there, Israel launched an attack. Using a combination of radar-jamming electronic warfare, radiation-seeking missiles and, according to international reports, early unmanned aircraft, the IAF destroyed 17 of the 19 batteries and downed 29 Syrian jets without suffering any losses of its own.

“That’s how it is,” said Rubin. “Air defense is always a game of cops and robbers, and once you know a system for some time, you get to know its strong points and its weak points.”

Before and after satellite images of the Syrian nuclear reactor at al-Kibar, which was reportedly struck by Israel in 2007 (AP/DigitalGlobe)

Before and after satellite images of the Syrian nuclear reactor at al-Kibar, which was reportedly struck by Israel in 2007 (AP/DigitalGlobe)

In September 2007, Israel reportedly exploited its technological advances to blind Syrian air defenses and strike and destroy Syria’s plutonium reactor in the far northeast of the country.

Subsequently, Syria set out to further modernize its aging defenses. That same year, Assad signed contracts with Russia for the Pantsir S1 mobile air defense units. Prime Minister Ehud Olmert reportedly met with then prime minister Putin to bar the sale, said Yiftah Shapir, the head of the Middle East Military Balance assessment at the Institute for National Security Studies in Tel Aviv. “But by 2009 it had arrived.”

The Pantsir batteries were the newest layer of defense, complementing the old Russian systems from the seventies and eighties. The Israeli news site Walla recently reported that Syria now has eight such batteries. The Wall Street Journal, quoting US intelligence officials, put the number at 36.

The discrepancy may be part of the public battle over the quality of Syrian air defenses, which began in earnest in late April when an Israeli general revealed what most Western intelligence agencies apparently already knew: Assad’s soldiers had used sarin gas against rebel troops. This revelation, a clear crossing of President Barack Obama’s red line, pushed the US closer to action in Syria and triggered a flood of leaks from the Pentagon.

When briefing the president or his staff, Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, frequently singles out Syria’s air defenses as the single greatest obstacle to US involvement in the conflict, the Wall Street Journal reported several days after the Israeli statement.

The paper quoted US intelligence and defense officials as saying that Assad’s air defense network was the most advanced and concentrated on the planet.

Rubin and Shapir agree that cumulative effect of the systems means Syria’s skies are densely protected but said that today, before the arrival of the S-300, the coverage is more tactical than strategic.

“The Pantsir units provide pinpoint coverage,” Shapir said, meaning that the batteries defend only small swaths of the sky and only from close range.

Technologically, the Pantsir is state of the art. In June 2012, a Pantsir battery shot down an American-made Turkish Phanton F-4 jet somewhere near the countries’ border line.

Yet judging by the airstrikes, reportedly executed by the IAF, in and around Damascus in January and earlier this month, their lock is easily picked. Many precision-guided strikes, said Shapir, appear to offer a path around the Pantsir.

This reportedly served Israel’s purpose of attacking specific weapons shipments. Establishing a no-fly zone — a constant blanket of air cover — is another story, as the Pantsir units are highly mobile and hard to track and could inflict losses on NATO aircraft.

Prime Minister Benjamin Netanyahu meets with Russian President Vladimir Putin in Jerusalem on June 25, 2012. (photo credit: Amos Ben Gershom/GPO/FLASH90)

Prime Minister Benjamin Netanyahu meets with Russian President Vladimir Putin in Jerusalem on June 25, 2012. (photo credit: Amos Ben Gershom/GPO/FLASH90)

Four units of the S-300 would further change the calculus. “They would cover all of Syrian airspace,” Rubin said, and “would be like a new lock on the safe.”

Rubin stressed that all locks can be picked and that Israel and the US possess the technological means to address such weapons systems, but he said they have yet to be tested on the S-300.

Al Quds al-Arabi newspaper claimed Tuesday that Assad’s army actually already possesses the S-300 system, but that it is under Russian control. This cuts to the heart of the matter: the extent of Russian-Syrian cooperation. More than the technological ability of each weapons system, the very fact of Russian involvement on the ground — in terms of technical support and strategic backing — is pivotal.

“The surface-to-air missiles are a small problem,” Rubin said, with varying degrees of severity. “The big problem is Russia itself.”