i think you're right to some extent, but keep in mind that if all the news, not a single incident, are being "properly" presented by the media, they can be used to create a very anti-american sentiment. imagine what a radically islamic version of fox news could do. and if you feed the idea that america is teh evil to people (that don't have much other ways of seeing the news) long enough, it will do a big part in motivating them to make their choice. it might not actually create terrorists, but it's definitely a huge help for terrorism recruiters.
good example:
http://www.islamonline.com