Iraq has been coordinating with Iran and sharing intelligence with them on fighting ISIS for some time, but as they’ve never been on great terms with the Assad government in Syria, the information sharing back and forth has mostly had to go through Iran as an intermediary.
That seems to be changing, as the Iraqi military announced plans to increase cooperation with both Syria and Russia, along with Iran, in an attempt to better coordinate the regional war against ISIS. The military cited “increased Russian concerns” about ISIS as part of the reason for the move.
Though ISIS is the primary rebel antagonist in both Iraq and Syria, and holds its territory contiguously across both nations, in many ways the ISIS war has been treated as two different wars in two different countries. This has led to a lot of focus shifting, particularly with the US picking and choosing whether Iraq or Syria is the “focus” at any given time.
The Iraqi coordination may rub the US the wrong way, as they are having only limited coordination with Russia and refusing to do much of anything with either Syria or Iran. Though Russia is unlikely to do anything inside Iraq to fight ISIS, the fact that they’re sharing intelligence back and forth may also give Iraq some leverage it didn’t have with the US-led coalition. US officials are expressing surprise at the move.
As the two fronts become a more coherent single warzone, the US policy is going to become increasingly murky, with officials backing the Iraqi government against ISIS rebels, opposing ISIS rebels in Syria but also opposing the Syrian government in favor of some largely imaginary “pro-US” faction.