You can not kill ISIS by killing ISIS. You have to kill the root of ISIS from where ISIS were born. That is Islam. Islam must either be reformed or destroyed for humanity to survive.
ISIS will not be destroyed
if you do not allow critical scrutiny of Islam,
if you do not stop brainwashing children with Islam,
if you do not stop building Quranic schools,
and if you do not abolish sharia laws.
The Quran inspires people to kill. The relation between Islam and violence, you like to hear or not, is very intimate. Muhammad the prophet started it, and his followers continued it.