The government of Iraq is now cooperating with Iran as the Iranian government is transporting military equipment to Syrian President Bashar al-Assad's regime through Iraqi airspace.
A U.S. official confirmed that Washington had warned “all levels” of the Iraqi government about letting Iran use Iraqi airspace:
It's reasonable to stop the planes and inspect them. At least do some randomly and legitimately to see. They (Iraq) have cause to be suspicious. Instead, they are suspending their disbelief, looking the other way, and averting their gaze. If they really wanted to find out they would stop flights randomly, periodically, and actually look at them. And we are confident that they would find, and we have told them this, military equipment and weapons, ammunition, those type of things.
The Iranian government has claimed that the planes only transport humanitarian supplies. Last December, it was reported that Iraqi government officials were warning Iran of the times when they would inspect the planes, rendering the inspections meaningless.