First, the logistics are terrible thanks to the Gulf War, sanctions, and airstrikes. As a show of force, Iraq tried to move some divisions to the Syrian border in the pre-Iraq War 2000s and simply couldn't even without any direct opposition. Collapsing sanctions and rearmament would mitigate this, but it would also mean a lot more butterflies.
Second, the Iraqi armed forces would have to wage an offensive expeditionary campaign on yet another Saddam adventure-I don't think the enthusiasm would be that great.
Third, a more direct option is to simply stop/hinder Iranian resupply. The Iraqi Air Force still exists and can block off much of its airspace (Although it would be hideously ironic if the Iranian transports could safely make it through the Kurdistan no-fly-zone enforced by the USAF.)
So I'm not seeing it-all there is is desert, a few nondescript cities, and oil fields that, assuming they aren't already destroyed, are still tiny compared to Iraq's own.