“What you gonna do? When you get down?” – Kool And The Gang
We have now heard Democratic and Republican candidates talk tough about defeating ISIS, but we have not heard the truth from any of them. The talk is tough; the strategy is vague. That is because they have no strategy, and the American people don’t want to hear the truth. We are playing their game.
The war against ISIS may take decades
Studies of the life-cycles of other insurgencies are remarkable consistent: they last over a decade  . The success of insurgencies that employ terrorist tactics are surprisingly low, but still long-lived. The local populace wearies of this type of war quickly, but usually finds itself unable to escape. The world is initially shocked and outraged by insurgent terrorists acts, but this is temporary, forcing the insurgents to perform more outrageous acts. Paris was such an act.
ISIS wants us to retaliate
“We also have to acknowledge that ISIL has been particularly effective at reaching out to and recruiting vulnerable people around the world, including here in the United States,” – Barack Obama
ISIS cannot recruit followers if they have no enemy. This is why they continue to goad us into battle with them. Our response is clumsy and expected. Bombs may hurt the caliphate, but small ISIS groups are forming in Pakistan and Afghanistan, and in countries all over the world. We cannot bomb them all. Meanwhile ISIS is plugged in to social media, delivering the message that they will vanquish the infidels. They are extremely flexible in their responses, and in stoking the anger in Americans and Europeans. ISIS needs enemies. Every bomb spreads their message. 
Spare the messenger – bomb the message
The most social-media savvy country in the world is acting like they never used social media. ISIS is an idea, and a bad one at that. There are many disillusioned young people who joined ISIS, and are now seeing ISIS for what it truly is, and we are not capitalizing on those people. We are not getting that message out.
The way to defeat an idea is with a better idea. It may be a different message for people in Afghanistan than it is for people in London, but we need to find out what will make people turn away from the ISIS promise. This is going to be a long war.
 Rand Corporation