U.S. military pressure can do a lot of damage to ISIS, but doing deep damage to ISIS is very different than actually destroying the organization or suppressing it for a period of time. That’s a big distinction that often gets lost. During the surge in Iraq in 2007, U.S. military pressure was a major component in weakening [al-Qaida], ISIS’s predecessor.
Military pressure will limit ISIS’s ability to plan and train fighters. It destroys equipment and kills fighters. Most importantly, it will remove their ability to set the terms of the conflict, because they’d be playing defense rather than offense. [They depend on their] mobility and ability to generate tactical surprise. So if you limit ISIS’s ability to plan and carry out campaigns, that’s a major blow to them.
What’s really important to recognize is that a U.S. strike hurts ISIS as an army. It forces them into smaller, spread-out territories. Even in a much-diminished state, ISIS is a strategic threat. And while that military push can force them into a smaller box and limit their power, this is an organization that will continue to do very brutal things and attract foreign fighters, and even though it’s taken on [the makings] of state and army, it is at its core an ideology-driven organization. That will make it very resilient.