The President made it clear for some time that he is not in favor of these wars. His advisors, Senior Civilians, and Generals had almost two years to figure out how to disengage and they did not get it done. The President probably grew weary of hearing that if we depart, ISIS will resurge in the political vacuum.
Violent Extremist Organization
A Psycho-Emotional Human Security Analytical Framework: Origin and Epidemiology of Violent Extremism and Radicalization of Refugees
The challenge of young-adult and refugee vulnerability to the spread of violent extremist ideology, subsequent radicalization, and devolution into violence related behavior.