We are working on the Syria portion of the supply line:
Syrian rebels say the United States and its allies are sending them more arms to try to fend off a new push into the southeast by Iran-backed militias aiming to open an overland supply route between Iraq and Syria.
The stakes are high as Iran seeks to secure its influence from Tehran to Beirut in a "Shi'ite crescent" of Iranian influence through Iraq, Syria and Lebanon, where Sunni Arab states have lost out in power struggles with Iran.
Strategypage looks at the Syria battlefield.
But we can't do much to stop Iranian efforts within Iraq given that the Iranians are guests to fight ISIL there:
An Iraqi Shi'ite force backed by Iran said it pushed Islamic State out of several villages on the border with Syria on Monday, potentially reopening a supply route to send Iranian weapons to President Bashar al-Assad.
The maneuver could also be the prelude to a connection with the Assad's Iranian-backed forces, although they are yet to reach the Iraqi border from the Syrian side.
I hope that an American decision to remain in Iraq in force after ISIL's caliphate inside Iraq is dismantled will encourage the Iraqi government to eject Iranian influence.
And as I've noted, Russia is unlikely to help Iran with this objective because Russia doesn't want Iranian influence in Syria to grow and because Russian objectives--air and naval bases--are secured with just western Syria in Assad's hands.
We're getting closer to a post-ISIL struggle surpassing the struggle to defeat ISIL.
UPDATE: America appears to be serious about blocking Iranian control (in Assad's name) of this supply line:
The U.S. military said on Thursday it had bolstered its "combat power" in southern Syria, warning that it viewed Iran-backed fighters in the area as a threat to nearby coalition troops fighting Islamic State.
We dropped leaflets to warn the Iranian-sponsored militias against moving into the area.
