Even after the group is defeated in Iraq and Syria, it will maintain the intellectual arsenal it has constructed for its supporters, so the U.S. should prepare for the next stage of the fight accordingly.
In August, U.S. President Barack Obama reassured the Pentagon that the Islamic State will "inevitably be defeated." U.S. government officials, generals, and pundits have been debating what could happen when the group is defeated in Iraq and Syria and have been hard at work penning ISIS obituaries. Based on my recent study, the first systematic review of over 150 Arabic language publications that the group has released since it announced a caliphate in June 2014 (which includes the nearly 100 textbooks it released last fall), it seems that ISIS as a lethal idea will stick around long after it will be driven out of Raqqa.
Put differently, while ISIS will eventually expire as a state, it will continue to "inspire" terrorism as an idea with lethal implications. Indeed, perhaps ensuring that the intellectual arsenal it is building outlives its territorial state, the group has published lengthy commentaries and manuals of religious guidance just as it suffered its greatest territorial defeats over the last few months. This is why the very idea of a promised caliphate will continue to inspire attacks when an actual one is no longer around...
Cipher Brief