Iran's allies in Iraq beat ISIS to border, seek to unite with Syrian army

Iranian Major General Qasem Soleimani, the iconic head of Iran's elite Islamic Revolutionary Guards Corps, was reportedly pictured with PMF forces at a border site in northwestern Iraq shortly after militias had secured it, signaling the importance of the event. Iran has also sent advisers and supported powerful paramilitary movements such as the Lebanon-based Hezbollah that back the Syrian military as it attempts to restore control of its side of the Syria-Iraq border. Iran is not only an ally of the U.S.-backed Iraqi government, but also of the Russia-backed Syrian government of President Bashar al-Assad, who faces a six-year insurgency from ISIS and various other rebel groups, some of which are backed by the U.S.
On the other side of the Iraq-Syria border site recently taken by the PMF lies territory held by the Kurdish-majority Syrian Democratic Forces (SDF), made up of Arabs and ethnic minorities. While the SDF has become the U.S.' main ally against ISIS in Syria, the group remains relatively neutral toward the conflict between Assad and Syrian rebels and has at times assisted Syrian army operations.
At another border crossing hundreds of miles away in the easternmost stretch of Iraq, however, the PMF have also made advances that could lead to potential conflict with militants supported by the U.S. Fighters for the PMF group known as Kataib Al-Imam Ali were seen on social media preparing for what they said was an incursion into Syria toward the border crossing of al-Tanf situated in the Badia region where Syria, Iraq and Jordan all meet. Much of the region is currently held by Syrian opposition groups backed by U.S. Special Forces and operating under the banner of the Free Syrian Army, a loose coalition of West-backed rebel groups.
The U.S. launched an airstrike against the Syrian army and allies earlier this month after claiming its vehicles came within 18 miles of the U.S. operations base near al-Tanf, sparking outrage from the Syrian government. The Syrian government has referred to the U.S.-backed SDF's struggle against ISIS as legitimate, but rejects any U.S. presence not coordinated with the local government or its Russian ally.