Sure, the Iranians will play a constructive role in Iraq.
They will govern it!
Maybe they can set up a few more centrifuges there to spin more uranium.
This is what happens when you leave a power vacuum. The closest bad guy(s) fill it.
Iran is about to own Iraq. Took a few decades but they are ready to take the spoils.
The concept of the power vacuum has been all but relegated to the ash heap of history.
Our withdrawing from to world stage, it’s going to result in something. Folks ARE NOT going to like it.
Sadly, they just can wrap their heads around that concept right now.
When they can, it will be too late.