If Tehran keeps trying to increase its military foothold in Syria, Israel may ramp up its strikes, so Washington should consider a more active posture that reduces the risks of escalation.
By striking Syrian antiaircraft forces and installations where Iranian personnel are located this weekend, Israel seems intent on forcing key players to recognize its deep interest in limiting Tehran's military presence in Syria. If Iranian leaders ignore this interest, they risk triggering a rapid military escalation.
In Israel, Prime Minister Binyamin Netanyahu and various military leaders have repeatedly stated that their main concern is avoiding Iranian military "entrenchment" on their northeastern doorstep. During his speech to the UN General Assembly last September, Netanyahu warned that Israel will not accept Tehran's development of advanced missile production capabilities in Syria and Lebanon, and that it "will act to prevent Iran from establishing permanent military bases in Syria for its air, sea, and ground forces." At a time when the Islamic Republic's main proxy, Hezbollah, is pointing more than 100,000 rockets at Israel, fears of a joint Lebanon-Syria front are growing.
The weekend clashes attracted international attention for a variety of reasons. They marked the first time an Israeli fighter jet has been shot down over Syria since the early 1980s. Moreover, the jet in question was part of an operation targeting an Iranian command center at a Syrian base—an unusual move given that Israeli strikes in Syria typically focus on discrete Hezbollah forces. The command center strike came on the heels of an Iranian drone infiltrating Israel, so the exchange could lead to further escalation.
Whatever the case, Israel seems keen on sending messages to several players:
The Assad regime. Although an Iranian-backed Assad victory in Syria is not in Israel's strategic or moral interests, Jerusalem appears to understand that it cannot decisively affect the war's outcome. It has therefore focused more on altering Iran's role there. Toward that end, it wants Damascus to realize the price of allowing Iran to house military personnel at Syrian bases. A number of Israel's strikes this weekend targeted bases far from the site where the drone was launched, so deterrence was likely as much a part of the game plan as retaliation.
To be sure, Bashar al-Assad is deeply indebted to the Iranians for helping to salvage his rule, so he cannot simply dictate orders to them. Yet if Israel continues exacting a serious cost because of Iranian involvement, Assad may feel compelled to request—whether directly or via Russia—that they dial back their presence. The regime has already shown signs of trying to persuade Tehran in this regard; according to Israeli officials, the Iranian chief of staff had to cool his heels during a recent visit to Damascus while Assad delayed signing any long-term military commitments.
When signaling Damascus, the Israel Defense Forces (IDF) seem to distinguish between the Assad regime's domestic military activities and Iran's role in backing them. Senior Israeli military officials have sent messages to Assad via third parties indicating that they do not oppose him extending his sovereignty in Syria on his own, but that they will view the situation very differently if he does so with Iran, Hezbollah, and Shia militias in tow.
Iran. The strikes were also intended as a warning that the IDF will not accept Iranian military activities or installations that threaten Israel. Contrary to some reports, such strikes are not a response to recent Iranian phosphate contracts or other economic moves in Syria. Rather, Israeli officials aim to hinder the development of major military infrastructure—seaports, airports, bases for Islamic Revolutionary Guard Corps units, or precision-guided missile production facilities for Hezbollah.
Israel has launched other strikes in recent months to define specific cases of unacceptable entrenchment and emphasize its redlines. In September, it reportedly hit a facility near the northwest Syrian town of Masyaf that IDF officials say was used to dramatically upgrade old rockets. In December, it struck a barracks for Iranian-backed Shia militias at al-Kiswah, within fifty kilometers of the Golan border. And it has repeatedly retaliated against Hezbollah for violating the de-escalation zone in southern Syria.
The United States. Following the latest strikes, the Trump administration issued statements supporting Israel's right to self-defense, but it has not provided any military assistance (at least publicly) for operations against Iranian forces in Syria. Washington has announced that it will retain some 2,000 troops east of the Euphrates River in northern and eastern Syria, but their mission remains unclear beyond defeating the Islamic State. The administration has also focused on managing Turkish-Kurdish tensions, with both Secretary of State Rex Tillerson and National Security Advisor H. R. McMaster visiting Ankara recently. In contrast, there are few tangible indications on the ground that Washington is actively trying to limit Iranian activity in Syria, apart from Tillerson's general statements that the continued U.S. military presence is partly designed to curb Tehran's local influence.
Some IDF officials have expressed hope that President Trump's frequent criticism of Tehran's regional ambitions presages a wider U.S. military effort against Iranian activity in Syria, but others remain skeptical. At the very least, a U.S. presence along the Syria-Iraq border could help prevent Iran from transferring weapons to Hezbollah and other actors by land. Due to array of political sensitivities, however, Israel will likely be careful not to goad Washington into direct military action against Iranian sites.
At the moment, it is unclear whether the risks posed by the weekend strikes will spur Washington to shift its policy in any way. For instance, will the threat of wider conflict between Israel and Iran make the administration more wary of escalation, more active in pursuing the Geneva peace talks toward a new political arrangement in Syria, and more willing to coordinate U.S. actions there with Turkey and Israel?
Russia. The author's recent meetings with political and security officials in Israel suggest that Jerusalem sees Russia as its best hope for constraining Iran's activities next door, at least in the short term. It is no coincidence that Netanyahu has visited President Vladimir Putin seven times in the two-and-a-half years since Moscow launched its intervention in Syria. Given Russia's own competition with Iran over Syria and its concerns about widening the war, Israeli officials hope that Moscow views IDF strikes as a welcome check on Iran's influence. They also believe that Damascus needs Russia more than it needs Iran, especially now that the objective of maintaining Assad's rule has been achieved.
Indeed, Russia has demonstrated a willingness to tolerate Israeli strikes, which offer a far easier means of constraining Iran's presence in Syria than doing so itself. Senior IDF officials are also very pleased that Moscow has not allowed Iran to build new military infrastructure near Russian facilities at Syria's Tartus port or Hmeimim Air Base—something Tehran has seemingly longed to do in order to deter attacks by Israel or other actors. In addition, Russia has refrained from using its advanced S-400 antiaircraft systems to prevent Israeli strikes.
Jerusalem does not publicly highlight these favorable steps, mainly to avoid embarrassing Moscow among its Iranian and Hezbollah partners. At the same time, however, Israel is sober about the limits of Russian influence. Although Putin seems willing to constrain Tehran's operations in Syria and deny its base requests, he has not taken any military actions against Iranian installations there. For now, the alliance with Tehran still serves Russia's regional interests, and the Kremlin's objectives are far more aligned with Iran's than with Israel's. The Islamic Republic has been a significant purchaser of Russian arms, and both countries have partnered with Hezbollah to keep Assad from being toppled.
Although Israel does not seek military escalation in Syria, it is determined not to let Iran develop the military capacity to change the equation on its northern borders. And Israeli officials will no doubt maintain this posture even if they have to keep acting alone, albeit with indirect assists from Moscow and Washington. This means that continued Iranian efforts to establish a military presence in Syria will likely be met with increased Israeli strikes. At a certain point, persistent Iranian efforts may convince Israel that deterrence has failed. Predicting that point is difficult, but if it is reached, the prospects of escalation in Syria and perhaps even direct Israeli-Iranian conflict will become far more likely.
David Makovsky is the Ziegler Distinguished Fellow and director of the Project on the Middle East Peace Process at The Washington Institute.