The historical evidence  suggests that terror campaigns that lose public support will eventually be abandoned, even if the terrorists themselves remain undefeated. As [Audrey Kurth] Cronin puts it, “Terrorist groups generally cannot survive without either active or passive support from the surrounding population.”
In a nutshell, this is why a primarily militaristic approach to terrorism is foolish. Killing terrorists is a useful thing to do, but even the most determined military assault is unlikely to work as long as terrorists retain public support. Until and unless that support is undermined, eliminating a terrorist threat is almost impossible.
Both the Sunni Awakening in Iraq and the recent experience of Pakistan demonstrate that terrorists are often their own worst enemies in this regard. The more they target civilians, the less support they have in the surrounding population. In Iraq we used that to our advantage to co-opt Sunni tribal leaders who had gotten tired of the violence and theocratic tyranny introduced into their communities by al-Qaeda in Iraq, and we should be doing the same in Pakistan.
In the long term, public support for terrorism is a far more important target than terrorism itself. It may not make as good a soundbite as a promise to follow Osama Bin Laden “to the gates of hell,” but figuring out how to get the Muslim public to turn against al-Qaeda and other likeminded jihadist groups ought to be Job 1 for any incoming administration.