The extent of any terrorist threat to the United States does not depend on killing any one organization. It will depend partly on those political processes in countries such as Iraq and Syria. It also will depend on how well the United States, in going after any one monster, does not create other ones. In that regard we cannot remind ourselves often enough—especially because this fact seems to have been forgotten amid the current discussion of ISIS—that ISIS itself was born as a direct result of the United States going after a different monster in Iraq.