The serious exchange of missile fire between Israel and Syria early Friday morning reflects the Assad regime’s attempts to change the unofficial rules of the game. These are the rules (according to foreign media) by which the two sides have conducted themselves over the past five years. This is a dangerous development, although signs of such a shift have been evident for several months now.

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At this stage, though, it doesn’t look like leading toward a wider confrontation between the sides. Israel’s relative military advantage over Syria is clear, and it’s doubtful whether Damascus is interested in dragging Israel into a war – one that from its perspective would wipe out all the achievements the regime has chalked up in recent months.

>> What role did Russia play in the Israel-Syria missile clash? <<

From what we currently know, between Thursday night and Friday morning Israel Air Force planes attacked targets in Syria (the air force’s recognition of this is the first time Israel has officially acknowledged such an attack since the start of the Syrian civil war). In response, rockets were fired into Israel from Syria. Apparently these were rather outdated, Russian-made SA-5 surface-to-air missiles. The Israeli planes were not hit, but one of the rockets, or a piece of one, was identified and intercepted over the Jordan Valley, north of Jerusalem.

The Israel Defense Forces operated its air defense system and launched an anti-ballistic Arrow missile, which intercepted the Syrian missile in the skies as it headed southward. Sirens went off in the Jordan Valley and sounds of the explosion echoed over the Jerusalem and Modi’in areas. A remnant of the Israeli interception missile landed in Jordanian territory.

The Syrian civil war erupted six years ago this week. Since the beginning of 2012, there have been foreign media reports of Israel Air Force airstrikes targeting convoys transporting weaponry from Syria to Hezbollah in Lebanon. Israel confirmed that it would act to thwart such shipments when they involve weapons systems that it defines as being a “game changer.” What this probably means is precision rockets, advanced anti-aircraft missiles and surface-to-ship missiles. Nevertheless, until the statement Friday morning, Israel has avoided making direct comment on the airstrikes.

According to reports in the Arab media, the convoys were only ever attacked when they were moving through Syrian territory; once they crossed the border into Lebanon, they were safe – Israel refrained from attacking them there. Usually, Syria held back after airstrikes on its territory. But the Russian decision to send jets to Syria, beginning in the fall of 2015, added a new ingredient to the mix.

Israel and Russia were quick to establish a coordination mechanism with the aim of reducing the risks of undesirable conflict in the air. At the same time, the Russians deployed radar systems in northern Syria that are able to observe what is happening at air force bases in Israel – as far south as the northern Negev.

According to the Arab media, Israel has slightly modified its operation patterns since then: Attacks on the convoys and weapons depots in Syria have continued – but the airstrikes are being done from afar. These are “stand-off” attacks, in which fighter jets launch their missiles from Israeli airspace or – according to other reports – from over the Mediterranean Sea, west of the Lebanese coast.

Israeli naval activity on the northern front has also changed. Israel Navy commander Rear Admiral Dror Friedman said on Army Radio this week that his fleet has sometimes had to cancel operational activity because of the physical proximity of Russian vessels.

After another visit to Putin

Since last September, Syria has occasionally fired anti-aircraft missiles at Israel Air Force planes (which are responding to shooting trickling into the Golan Heights). What is different this time is the Israeli response: A Syrian anti-aircraft missile penetrated Israeli airspace and, had it landed, may well have endangered civilian lives. The decision to intercept it using an Arrow missile led to an aerial incident that couldn’t be concealed: Many civilians were woken by the sounds of explosions and sirens. As a result, an official statement was released.

The firing at the anti-aircraft missile is itself exceptional. The Arrow was developed to deal with long range, surface-to-surface missiles. In recent years, the Arrow II system was upgraded to deal with anti-aircraft threats as well. Nevertheless, it seems the air force will now examine whether there was full operational justification for the exceptional interception – the first operational firing of an Arrow missile that Israel has officially reported.

Presumably the Syrian anti-aircraft salvo was a signal to Israel that the regime’s policy of restraint in the face of the airstrikes will not remain as it was. President Bashar Assad’s recent successes – first and foremost the conquest of Aleppo – have seemingly increased the dictator’s confidence. Israel will have to decide whether the operational need – to thwart advanced weapons shipments to Hezbollah – also justifies the possible risk of the downing of an Israeli fighter jet and a broader conflict developing with Syria.

There is an interesting question as to whether the aircraft detection radar system was deployed by Israel’s new great friend, Russia, precisely one week after Prime Minister Benjamin Netanyahu returned from Moscow after yet another successful visit to see President Vladimir Putin.

One can imagine that the intelligence community will also be interested to learn whether the Syrian decision to fire back was coordinated with Assad’s collaborators and partners: Russia, Iran and Hezbollah.