Was the Rise of ISIS Inevitable?

In The News Piece in CATO Institute
June 6, 2017

David Kilcullen was quoted in a CATO Institute blog post about the rise of ISIS: 

David Kilcullen, who worked on counterterrorism at the State Department in 2005-06 and was senior adviser to General David Petraeus at the height of the Iraq surge in 2007-08, put it even more bluntly: “There would be no ISIS if we had not invaded Iraq.”