It's understandable to assume that the violence in Iraq which began after the blitz of ISIL last month won't subside anytime soon. But there are some realities to reflect upon.
All Al-Qaeda categories are notoriously slack fighters, lacking in leadership skills, discipline, battlefield strategy and worst of all, rife with infighting for power and money as the prime goal. They probably would never be able to capture Mosul despite the incompetence of the Iraqi army if they weren't helped by Baathist forces and the Naqshbandis. No Al-Qaeda group has yet been able to face a real army alone without massive and steady assistance from the West via the GCC. Since the inception of Al-Qaeda, not a single incident shows the success of this organization when it stood and fought independently. It tried to do that in Afghanistan in 2002 and was routed. Events in Syria are no less discouraging for them. In spite of support and benefits worth billions of dollars from the West and their gulf allies for more than three years, none of the Al Qaeda franchises have yet acquired a solid and widespread victory against the Syrian Army, much less threatening the fall of the Syrian government. What we're seeing is the mercenaries' hide-n-seek tactics with the Syrian forces and also within themselves. ISIL's sudden decision to move away from Syria to Iraq is basically the outcome of its poor performance and total lack of success on Syrian battlefronts. If cornered in Iraq, rushing back into Syria wouldn't be an ideal option either.
With Iran and Iraq seriously planning to coordinate and the Syrian air force already pounding ISIL hideouts along its border with Iraq, if the US and EU decide to mind their own businesses for a change and halt their subversive policies, ISIL would be in hot water. With that, the incentive of the Baathists seeking alliance with ISIL would taper off as well. The presumed cooperation of the Baathists with ISIL is more an act of the former's bitterness against Shiia post-Saddam Iraq rather than any ideological compatibility with the latter. Baathists have always been staunch secularists who have never had a soft corner for reactionary movements, let alone ragtag ones like ISIL promoting Western interest.
As is obvious, the US and EU are in no hurry to help Iraq repulse ISIL just as they aren't in Syria. Why would they be? After all, ISIL is their initiation and their brand of high-priority mercenaries. On rainy days it's these obscurantists who do the rough-n-tough assignments necessary for 'first world' expansionism. A friend in need is a friend indeed. Coping with ISIL's tantrums is an indispensable investment for the West. The West isn't considering to fight ISIL any time soon. But just as long as it doesn't feed them might be enough for the survival of Iraq as an entity.
Confronting ISIL in Iraq now depends largely upon the stance taken by Iran. According to recent reports Iran had expressed its willingness to help stop the advance of ISIL and decided to send an entire fleet of fighter jets to Iraq. Needless to say, Iraq isn't capable of handling the situation on its own. The $20 billion training imparted to Iraqi forces by the US was only on torture techniques, not combat skills. Iraq's dependency on the US would only make it weaker at the hands of ISIL.
United States' support for Shiia Iraq was on the rebound following the fall of Saddam. But that's water under the bridge. The story is altogether different at the moment. The United States (and Israel) now sees Iraq as Iran's ally. Consequently it has also acquired a partner of convenience within the various Salafist camps that are sworn enemies of Iran, Iraq and Syria. The need for promoting Zionist hegemony in the Middle-East has never been more for which Iran and Syria are seen as formidable obstacles. As it would be simple enough to gauge, United States is no longer interested in pampering the immediate successors of Saddam whom it brought into power after toppling the Baathists a decade ago.
With the Syrian Army and Hezbollah taking care of Levant and its borders with Iraq, now is the time for Iran to act jointly with Iraq. Otherwise there is a huge possibility that optimism could be lost sooner rather than later.