Well we could level the playing field.
If it comes to blows with Iran, we could mount an air and naval war against them to bring them to their knees. Imagine what 5 or 6 carriers plus cruise missiles and our long range bombers could do to Iran during several months of nonstop bombing. The 100 day bombing campaign against Iraq in 1991 crushed the Iraqis, it could do the same to Iran.
By setting Iran back several decades economically, militarily, and politically, we'd level the playing field enough for Iraq to get back on its feet. The Iranians would be too overwhelmed repairing their own shattered infrastructure and military to interfere with Iraq.