ISIS isn't strong. It's weak. That doesn't mean it's not dangerous, or that it can't hurt us. But we shouldn't pretend these are invincible superterrorists. They're murderers fighting a war that they will lose and we will win. Part of how they recruit young fighters is by pretending that's not true — pretending they have a chance in this fight, that they are strong, that they have the West on its heels. We shouldn't indulge their fantasies. We can mourn their victims without believing their propaganda.
The thing you need to remember about ISIS, says Gartenstein-Ross, is it is not just weak in the West, it's also loathed across the Middle East: "America is unpopular in the Middle East, but if we had ISIS's approval rating, we would see that as a very, very serious strategic problem. They have a terrible brand. So part of what we need to do is simply avoid making mistakes that will let them present themselves as a defender of Muslims. We need to make sure Muslims continue to overwhelmingly reject ISIS."