It is dangerous on so many levels. They are creating their own Islamic state. This is the stated goal of Jihadis everywhere and specifically the vision Osama Bin Laden laid out when he declared holy war on the United States and all Western Civilizations. To bring back the Caliphate...a region dominated by Sharia Law where anyone not converting to Islam will be murdered as Infadels.
Aside from that...having a state in which to meet and train and plan is exactly what happened in Afghanistan where they planned and executed 9/11They say the leader of ISIS is ever more ruthless and more evil than OSama Bin Laden was. As they capture more territory...aside from emptying the prisons and banks...they have seized thousands of vehicles like humvees, ammo, helicopters, etc They are a legit army.
This is what happens when America withdraws from the world. Had we kept a force of 10,000 troops in Iraq this group would not only not come as far as they have...but the Iraqi military....which has been running away from the fight...would certainly have stiffer spines if they were back with 10,000 Americans soldiers.
We need to stay engaged not to protect Iraqi's but to protect OURSELVES.I say we go in for Shock & Awe round 2 and this time, we never leave.