From the perspective of aerial defense, this Israeli red line is crucial, for if Iran is allowed to set up air bases in Syria, the entire strategic picture will change for the worse as it pertains to the Middle East.
Iranian air bases in Syria would mean that instead of having to fly 2000 kilometers to reach Israel, Iranian jets would be stationed 200 kilometers from us.
A 2000 kilometer flight requires mid-air refueling and prior intelligence. It is not an easy operation to undertake. But a 200 kilometer air journey is much simpler.
This proximity would also allow the Iranians to have a better intelligence picture of Israel. It would obligate Israel to intensively collect intelligence on any new Iranian military assets sprouting up in Syria.
From a geographical, military perspective, Iranian airbases in next door Syria would be a game changer. Presently, the Iranian enemy is located mostly to the east, and can, to a limited extent, attempt to attack from Israel's north and south. But it cannot come from the West.
If Syria becomes home to Iranian aerial platforms, Iran could head west to the Mediterranean Sea, and then fly toward any Israeli coastal city; be it Haifa, Tel Aviv, or Ashkelon. The same holds true for Iranian drones.
This would mean opening a new western front against Israel that requires an entirely new line of defense—a front that does not exist today. Such a development would represent significant danger to Israel.
THE RISK OF A COSTLY MISTAKE
In addition, the presence of Iranian aircraft in Syrian skies would greatly complicate the job of deconfliction with the great powers of Russia and the US.
At this time, Israel has full air superiority in the northern arena. Syria has very little left in the way of an air force after five years of war against the rebels. The majority of planes flying over Syria are usually American or Russian.
But if the Iranians suddenly start to appear over Syrian skies, Israel would need to work hard to ensure it can correctly identify them, and differentiate between Iranian, Russian, and American aircraft.
The dangers of shooting down a Russian fighter jet are familiar to Turkey, which suffered a significant punishment from President Putin following the November 2015 incident in which this occurred.
Enemy Iranian aircraft appearing in Syrian skies—interspersed among the air traffic of Russia and the US—would undoubtedly raise the risk of Israel bringing down the wrong fighter jet by accident.
A NEW PHASE IN IRAN'S POWER PROJECTIONS
Until now, Iran has mostly threatened Israel by proxy, just as it threatens Saudi Arabia via the Houthis in Yemen. Hezbollah and Hamas have served as Iranian proxy threats against Israel. Yet if the Iranians begin inserting themselves directly into the Syrian arena, they will bring with them more sophisticated capabilities to target the Israeli home front.
Israel would struggle to level the playing field in terms of wielding a reciprocal threat to the Iranian home front. Israeli forces would have to travel 2000 kilometers to reach Iran. But Iran would have a permit to get close to Israel if it is allowed to set up shop in Syria.
Such a scenario carries the distinct possibility of dragging Israel into the Syrian arena, something Jerusalem has tried to refrain from doing until now. Israel's policy in Syria has been limited to providing humanitarian assistance to civilians, caring for wounded Syrians, and enforcing Israeli red lines, according to media reports.
Even now, Iran is attempting to traffic precision-guided weapons into Syria, efforts that Israel is reportedly disrupting in a pinpoint manner.
If the Iranians arrive in Syria as a permanent military presence, they will bring more sophisticated weapons, including more advanced rockets and drones, and share them with their proxies. This would form a complex and dangerous threat.
HOW TO AVOID EXAPNDING THE WAR IN SYRIA
This assessment is not designed to cause alarm. Rather, it clearly spells out the significance of an Iranian military presence in Syria.
The Israel Defense Forces (IDF) remains the strongest military in the Middle East. The Israel Air Force is by far the strongest in the Middle East, and one of the leading air forces in the world. Its platforms—the F-35, F-15, and F-16s - are among the most advanced in existence. Its air defense systems—David's Sling, the Patriot, the Arrow systems, and Iron Dome, as well as Israel's drones and air command, are highly advanced.
Even if Iran consolidates itself militarily in Syria, Israel would not face a catastrophe, and would emerge victorious in the event of a conflict. But this would certainly increase the chances of a war in the short or medium term.
War should be the last option, not the first, and for this reason, it is vital to prevent Iran from moving into Syria.
Brigadier-General Shachar Shohat (Res.) commanded the Israel Air-Defense Forces from 2012 - 2015