You can't blame Bush any more, Obama. Even your closest advisors say that the Iraq you "inherited" was in a state of calm that had not been witnessed before the time of Saddam Hussein. You felt that way yourself, apparently, because you decided to immediately withdraw U.S. Troops entirely from the region without even leaving a small residual force in place. Against all advice and opposition, you surrendered Iraq to chaos.
It's difficult to consider the impact of the lack of leadership you displayed in Iraq. To announce a time line for U.S. withdrawal was perhaps the worst decision, a political decision designed to appease your pacifist left-liberal supporters. Of course, ISIS would take the opportunity to plan strategy, organize, arm, and wait for the U.S. withdrawal so it could effect an assault on Mosul, Tikrit, and other key Iraqi cities.
If there is any good news, it would be the surge of the Peshmerga Kurd troops into Kirkut, their historical center. You can understand that they have as much a right to claim that, especially with the government troops fleeing it, as the Russians had to claim Crimea.
It's chaos, and President Obama has no answer for it. The answer should have been ready and waiting before you announced a pullout timetable. Now there are no operatives or troops on the ground and we are reduced to getting vital information from news outlets which are as clueless and opinionated as you are.
Fortunately, CNN --your unofficial dispatch offices-- will trumpet that you are considering alternatives. And considering alternatives. And considerating alternatives. And consulting, And studying. All of this is what you've done with Libya, Syria, Iraq, Afghanistan as you destabilized these countries and others.