For the first time since the Islamic Revolution of 1979, Iran is on the verge of acquiring a direct land link to the Mediterranean Sea and southern Lebanon. Iranian proxies and Assad regime forces advanced south in the Syrian desert on Friday to reach the Syrian-Iraqi border, cutting off Free Syrian Army rebels who had hoped to traverse that same territory to fight ISIS in the east.

Barring a Pentagon-backed rebel counterattack, Iranian proxies are now on pace to complete their corridor through a combination of advances south on the Iraqi side of the border and advances north and east on the Syrian side. On the Iraqi side, Iran-linked Popular Mobilization Forces (PMF) groups reached the border in a lightning offensive last month. The Institute for the Study of War records that before the offensive, PMF groups had already attained a direct line of control from the Iran-Iraq border to Tel Afar – their forward position on the eve of the lightning offensive.

Now, a similar lightning offensive has occurred on the Syrian side of the border. The Iranian pro-regime media station Tasnim News released multiple photos today from the Syrian-Iraqi border showing IRGC-Quds Force head Qassem Suleimani alongside members of the Fatimiyun Brigade, which is a force of Afghani foreign fighters in Syria backed by the IRGC. Iranian-backed militias from Iraq including the Imam Ali Battalions, the Imam Baqir Brigade, and the Jihad Brigades had all increased their presence in the Syrian desert in the weeks prior to last Friday’s advance.

While many miles still separate the Iran-backed militias’ in northeastern Iraq and southwestern Syria, the militias are highly likely to link up if only ISIS-held territory stands in their way. Iranian and Assad regime forces were able to make rapid gains against ISIS in the Aleppo suburbs after boxing in rebel forces in the area of Al-Bab town. This past Friday, rebel forces in the Syrian desert might have been boxed in in a similar fashion.

It is important to note that pro-Assad forces launched few operations in the south Syrian desert until Free Syrian Army rebels began making gains against ISIS in the area this March and April. Assad forces then declared the area a priority – but they and their Iran-backed allies attacked the FSA rebels, not ISIS. Furthermore, pro-Assad attacks against rebel forces only began in earnest as the Russian “de-escalation zones” initiative took effect. Iranian Quds Force head Suleimani reportedly urged his proxies to build a ground corridor “before the Americans get there” around this time.

Shlomo Bolts is the policy and advocacy officer at the Syrian American Council in Washington D.C., where he prepares analysis and presentations regarding the ground situation inside Syria to facilitate policy papers, reports, op-eds and briefings with senior officials in the government and Congress.

[Photo: Tasnim News]