We disbanded the Waffen SS, too
Following Germany's surrender, the Allies disbanded their military. A few years later, it was recreated to confront Soviet aggression. Was it an error to disband German military, especially the Waffen SS? Hardly. And it was no more an error to disband the Iraqi Army, especially the Republican Guard (the closest analog to the Waffen SS) so it could be rebuilt from scratch. It needed extensive rebuilding. Most if not all of the former Iraqi officers got their position by being Saddam loyalists. They didn't have anything resembling a professional NCO cadre (the true backbone of any capable military).