The media is a great way to implement cultural change. The media has a huge influence amongst all classes of citizens. Depending on how they are used and how they present information, they could unite or divide a country. One could use the media to deglorify crime and violence and make the country more peaceful. America in particular glorifies violence and crime. It has a high number of inmates, who could be potential terrorist recruits. In an idealistic world we would prevent terrorist attacks before they even begin. To do this you would punish the leaders who allow the attacks to happen because they are corrupt. We would have leaders who live and lead ethically ("How to prevent domestic terrorism").
Another way to implement cultural changes is to prevent offenders from wanting to join these terrorist organizations. To do this you must provide them with incentives to stay clean from crime. Programs to help criminals stay out of trouble can be costly though. The countries population must be willing to pay for and invest in them (through taxes most likely) ("How to prevent domestic