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In recent weeks, supposedly civilian Iranian aircraft have turned around after trying to land in Syria.
Mahan Air, Pouya Air and Iran Air often make these trips without incidents – although Israeli air strikes have hit Damascus and Aleppo airports, at times after the aircraft land, an Israeli security analyst told The National on background.
It is unclear why the aircraft have recently aborted their missions, but they could have decided proceeding was unsafe after a warning or the close presence of Israeli jets. Iran's cargo planes are subject to western sanctions, accused for more than a decade of flying arms to Syrian President Bashar Al Assad, his allies in Iran’s Islamic Revolutionary Guards Corps – and Hezbollah.
Israel, meanwhile, has discarded red lines in the current war, killing senior Iranian generals in a strike on Iran’s Damascus embassy compound on April 1, which prompted the latest cycle of escalation, including ballistic missile attacks on Israel.
Israel's Syria strikes are part of a campaign of weekly attacks against suspected Iranian weapon shipments, mainly intended for Lebanese Hezbollah.
Since October 7, the group has been under pressure from Israeli air strikes, after it opened a front against Israel, after the start of the Gaza war. Those strikes are not just in Lebanon – where nearly 2,000 people have been killed in bombing, but in Syria, too.
Israel has admitted to thousands of strikes, although rarely commenting on individual actions. But they are said to be almost entirely against Hezbollah weapons storage and supply lines through Syria, as well as IRGC, Syrians and Iraqis assisting them.
Israel's war between the wars
The so-called “campaign between the wars” began on January 2013, when the Israelis bombed anti-aircraft missiles en route to Lebanon. Three months later, Hezbollah leader Hassan Nasrallah said Syria would provide the group with “game changing” weapons.
Syrian special weapons research sites in Masyaf have also been bombed and, possibly, raided, a part of this linked campaign.
“The campaign didn't really stop the transfer of missiles, because even if we were able to stall them, Hezbollah moved to indigenous production," says Danny Citrinowicz, a 25-year veteran of Israel defence intelligence.
"It produced its own missiles, accurate missiles. It managed to transfer highly sophisticated capabilities. So in that regard the campaign was stalling, but not depriving. But what it really did, it really prevented the Iranians from building a second front from Syria."
The rise and fall of Syria's air defences
Syria once had the deadliest air defences in the Middle East, with thousands of anti-aircraft missiles dotting the country. At the start of the 1973 Arab-Israeli war, the Israelis lost six US-supplied F-4 Phantom jets trying to bomb air defences near the Golan Heights. Israel eventually won the upper hand, bombing Damascus on October 9 – 51 years ago today.
Syria then expanded air defences, including in Lebanon’s Bekaa valley. During the Israeli 1982 invasion of Lebanon, equipped with US F-15 fighter bombers, Israelis shot down 86 Syrian aircraft for two F-15s being damaged.
Operation Mole Cricket 19, saw 30 Syrian anti-aircraft sites bombed, with the Israelis using Samson decoy drones. Syrians wasted missiles on the decoys and exposed their positions – which were destroyed by radar-seeking missiles.
Israel raided Syria again in 2007 to destroy a nuclear research site in Deir Ezzor. Analysts claimed the Israelis hacked into Syria’s linked air defence system, knocking it offline, or used an electronic warfare system called Senior Suter to send false radar signals to enemy defences. Syria then updated its air defences with new Russian equipment.
These tactics, from decoy drones to false radar signals, were part of a decades-long process in modern electronic warfare to “crack” enemy air defences, says Thomas Withington, an expert in the field. Many of these “Suppression of Enemy Air Defence” tactics are still used, including the decoy drones which became a US-Israeli project, the Tactical Air Launched Decoy.
The long war, he says, is part of an continuing evolution of modern combat.
“The SA-2 and SA-6, which were used by the Syrians, were in the 1950s and 60s the feared Soviet medium to long range, medium to high altitude SAM system, that allowed Vietnam to shoot down so many American planes, and the Israelis had to fly against them.
“Then we get to Gulf War One, and we get to the Balkans, and we get to Libya. And the fundamental takeaway is that those systems are ineffective. And the reason they're ineffective is because of all of the effort that the US and the Israelis spent to defeat them. The S-300 and the S-400 risk going in that direction.”
By 2011, when a major uprising against Bashar Al Assad erupted across the country, Syria’s air defences were still a force to be reckoned with. The air defence command had up to 40,000 personnel and 150 SAM batteries. Each battery of SA-5 missiles comprised six launchers.
Syria could flood the sky with missiles, presenting a serious threat to Israeli aircraft, despite the fact that many of the systems were ageing. Israel became more aware of this in February 2018 when it lost one F-16 and suffered damage to an F-15 in two rounds of Syrian SA-5 attacks involving up to 30 missiles.
But the uprising had seen much of the country fall into rebel hands, along with airbases and anti-aircraft batteries. Israel exploited this weakness to hit harder at Hezbollah’s supply chain. That supply chain, according to Hezbollah expert Matthew Levitt, was built up following the 2006 war with Israel and boosted by Hezbollah’s intervention in support of Assad in the civil war.
According to Israeli analyst Yaakov Laapin, 800 targets were bombed in this campaign between 2016 and 2017 alone. Brigadier General Amnon Ein Dar said that “thousands” of missions had been conducted.
The 2018F-16 incident was a rare success for the Syrians, but resulted in retaliation that, according to Israeli estimates, destroyed one third of the country’s air defences. Two months later, Israeli F-35s entered service. The almost undetectable stealth bomber was soon hitting targets, despite the presence of advanced S-300s lent by Russia to reinforce Syrian air defences.
Mr Withington says this move – intended to help the Syrians – could prove dangerous for the Iranians, who use the S-300. F-35s have the capability to analyse enemy radar signals and store them in a database, a processor on the jet called the Automated Logistics Information System. In Iran, that could allow instant recognition of what enemy defence crews are doing.
Air defence battle
Even with this knowledge, the Israelis have likely faced challenging missions. Some analysts believe Iran has sent new Khordad-15 missiles to Hezbollah through Syria, as well as basing them in the country.
“All systems eventually yield their secrets. But the problem with any air defence system is that in order to defeat it, if you're going up against S-300s, there will be a very particular set of processes that you use to try to defeat any radar that is either searching for you or has locked on to you.
“You've got to execute them in a precise sequence in such a short amount of time. And if you get one of those things wrong, the radar continues locked. Aircraft electronic warfare systems now try to do as much of that automatically as possible, but there's still a set sequence that you have to follow.”
Whether or not Iran has transferred Khordad air defences to Syria, for now, the Israelis have the upper hand, Mr Citrinowicz says. But while this is a setback for Hezbollah, he says the main dilemma is one for Assad.
“Assad was ready to co-operate with Iran and Hezbollah, but I think he was fearing for his own life or survival of the regime, so he's preferred not to directly intervene. The Israeli campaign really highlighted Israel's capabilities to him,” Mr Citrinowicz said.
