By David L. PHILIPS*/The  Jerusalem Post/

The  Kurds are critical to containing Iran and its Hezbollah allies in Syria. President Donald J. Trump’s decision to quit Syria opens the door for Iran to expand its influence in Syria, jeopardizing Israel’s security.
Iran seeks to control a corridor from Tehran, through Iraq and Syria to Lebanon. The corridor would serve as a conduit for transporting missiles and other heavy weapons to Hezbollah. Kurdish militias, comprising the People’s Protection Forces (YPG) and the Women’s Protection Units (YPJ), have stood in the way blocking Iran’s ambitions.
Without US assistance, the geostrategic balance will shift in Syria. Turkey will invade; Kurdish forces will either be massacred, or flee and disburse. Iran and Turkey are forging a partnership. Israel has much to fear from their transactional alliance.
Iran’s insidious influence in Syria is a sordid story. It expanded its presence in 2011 and 2012, as the civil war spiraled out of control. Saving Assad and his Alawite regime became a strategic obsession for Tehran, which views Syria as a vital frontier in the struggle between Shi’ites and Sunnis. Syria became the front line in Iran’s sectarian struggle with Sunnis, and the launch point for attacks on Israel.
Tehran deployed the Iranian Revolutionary Guard Corps (IRGC) and Hezbollah as foot soldiers in Syria’s civil war. About 60,000 IRGC members and thousands of mercenaries from Afghanistan, Pakistan, and other countries joined the battle. Israel strongly opposed Iranian operations on its border with Syria, fearing sophisticated missile technology capable would overwhelm its Iron Dome missile defense system.
Hezbollah, acting on Iran’s behalf, proved indispensable to Assad. In 2013, Hezbollah captured Qusair, which prevented Sunni Arab rebel fighters from seizing Damascus. Hezbollah played a major role capturing Aleppo in 2016. It led the fight in Homs and Damascus suburbs like Ghouta where chemical weapons were used.
Beyond manpower, Iran became increasingly invested in Syria. It spent $36 billion in Syria between 2013 and 2017. It sponsored foreign fighters at a cost of $100 million annually. Between 2011 and 2015, Iran’s Trade Development Organization provided Syria with a line of credit of $5.87 billion. Iran also provided $2.8 billion in humanitarian aid.
Assad tried to mollify Israel, expanding cooperation with Iran at the same time. He adhered to the 1974 disengagement agreement with Israel in order to avoid an escalation that might distract from Syria’s civil war. Israel could not, however, ignore Iran’s operations in Syria. Between 2016 and March 2018, Israel bombed at least 100 Iranian convoys delivering weapons to Hezbollah. In early 2018, an Israeli Apache helicopter shot down an Iranian drone launched from the Tiyas air base (T4) in Homs province. Iranian surface to air missiles downed an Israeli F16. The shadow war turned kinetic when Iran fired a barrage of 20 Grad and Jafr 5 ground-to-ground rockets against Israeli targets in the Golan Heights on May 10, 2018.
The Kurds, secular and pro-western, helped keep Iran at bay. The Kurds control 30% of Syrian territory, serving as an important check on Iran’s power and influence.
The balance of power changed when Trump announced the withdrawal of USA forces from Syria. Not only did he sacrifice the Kurds who fought alongside US Special Forces against the Islamic State since 2014. He conceded the battlefield to Turkey and Iran, giving Hezbollah free rein to attack Israel. The Kurds acted as a check on Iranian influence. With US support, they also kept Turkey at bay.
All that will change when US forces are withdrawn. Iran, Turkey and Russia will fill the vacuum by more completely carving Syria into zones of influence. Iran will strengthen its military position along Israel’s border and strengthen Hezbollah.
It is not too late for Trump to modify his decision to quit Syria. The Israeli government should emphasize the critical role of the Kurds, urging the US to maintain its troop presence in northern Syria.
Prominent Jewish organizations in the United States, like the American Jewish Committee and the American Israel Public Affairs Committee, can advocate on behalf of the Kurds, underscoring their importance as a counter-balance to Iran.
America’s support stabilizing Syria resulting in its successful political transition would enhance Washington’s efforts on other regional peace issues.
Syria has become a proving ground for Iran and Hezbollah, which represents a clear and present danger to Israel. If the Trump administration is concerned about Israel’s security, it will maintain support for the Kurds.

* David L. Phillips is director of the program on peace-building and rights at Columbia University’s Institute for the Study of Human Rights in New York. He served as a senior adviser and foreign affairs expert to the State Department during the presidency of George W. Bush. His latest book is titled ‘The Great Betrayal: How America Abandoned the Kurds and Lost the Middle East.’