Who would win in a war, Saddam Hussein and the Iraqi Army that he commanded, or Nouri al-Maliki and the current Iraqi Army.
Maliki has two advantages that I can think of: 1. He's a Shia and most Iraqis are Shia so they'd probably support him 2. His army was trained and supplied by the U.S., and probably has newer and more advanced weapons and equipment
Hussein has a few advantages: 1. Maliki's army has 14 divisions, but 5 of them are considered combat ineffective 2. Maliki's troops retreat too much while Saddam's generals feared him 3. The Republican Guard 4. He has had, and used, chemical weapons.
I'm gonna say Hussein would win, there's no way ISIS would've been able to dislodge his forces from so many cities. Maliki's guys would turn and run, whereas Hussein's guys probably wouldn't retreat because they'd probably get killed if they did (or at least their commanders would be). Plus if Maliki's forces did actually start to gain the upper-hand by strength of numbers, Hussein would probably order mustard gas attacks or other chemical weapons attacks.