http://www.nytimes.com/2016/07/26/world/middleeast/isis-iraq-insurgency.htmlGuerilla war from ISIS will be a problem. How the USA and Western forces deal with radical ideology in the future will determine whether ISIS survives or not.
You can defeat them through conventional war. The idea still survives on. Surprise attacks will still occur. More attacks have occurred because of their losses of territory. They are getting desperate. More attacks will happen. In fact, they have sleeper agents that are waiting for the order to do attacks.
http://time.com/4438388/abu-mohammad-al-adnani-isis-emni-profile/http://www.nytimes.com/2016/08/04/world/middleeast/isis-german-recruit-interview.html/This will be a problem even if they lose all their territory. The extremists will still exist.
Support for groups like ISIS will depend on how much people believe in the narrative that the West is waging war against Islam. It will be critical to fight this narrative or these extremist groups will continue to live on forever.
Another concern is Saudi Arabia and other countries in the Middle East fighting a proxy war with Iran. ISIS is one of those groups that the Saudis are providing assistance to in order to fight Iran. This is another problem that must be addressed if people want to reduce Islamic extremism.
Edited 8/6/2016 07:27:04