Usual interpretation of the concept of ideology teaches us that ideology is the pure and simple set of organizing ideas generated by the ruling elite, as if, in the momment of generating ideology, the burgeoise class was able to unite themselves as a single voice. This would make ideology the result of a public aparattus of non-contradicting theory, almost like a parallel science (This can be partially true in a police state, but no one ever reaches total control over culture). Ideology, being just a legitimizing discourse and not a true search for the truth (in the sense of a scientifical discourse) must adapt first to political interests of the one who speaks, his on personal prejudices, his standpoint as member of a social class, his standpoint as a historical man, from a certain country, from a certain era etc. So, in the light of the aforementionated biases, man - as the creator of culture - imprints his own set of views in the art and leisure it creates. On the other side, on those who are receptors of the culture, its consumers, a certain set of deeply held beliefs and prejudices work as to modulate the culture he is interacting with. For the proletariat, partially unconscious about their own class interests, and so lacking something that would protect it from the ideological unslaught, this means accepting a burgeoise discourse as if it was his own. Culture is not a monolithic structure created top-to-bottom, but a live group of ideas (and so people) that constantly interacts with each other, destroying culture, recreating culture etc.
For one, when hollywood produces a movie about a terrorist attack on an airplane, they do so embeddeding into it a set of interpretations for the motivations of the terrorists (not as if they simple decided to defend oficial version, but because the oficial version of history is their only source of explanations for the events), they do so from a point of view of a certain subset of the rulling class of USA. If this same movie becomes an international sucess, reaching audiences from all over the world, this results in an effect where the culture (and so the interests) of a specific class of USA groups becomes common sense in the minds of the people from other countries.
If scientifically we might connect terrorist activity with the belligerant thought of islam, fundamentalism as a defense against imperialism, a certain patriarcal masoquistic attitude to life (were commiting the uttmost act against ones own body - death - is seen as - simbolically - better than feed its own eartly desires) and other factors that can very well escape scientifical thought, ideology comes to create a simplistic set of ideas that can explain the reasons behind terrorist activity without touching the core historical problems that can explain the events in much more depth.
But this is not only because ideology is simpler. In politics we must resort to plans and programs, that are the necessary result of a set of problems being faced by a historical group as a whole. To put it in another way, if USA has problems with terrorism, the whole country needs a answer to it, a group of ideas (a project) that must be implemented to solve said problem. But, if the problem is faced by almost the whole country, the solutions are not necessarely in the interests of this whole country. So, the thinkers of each class develop ideas to form their own programs on how to solve this collective problem. This is a class program.
So, when hollywood produces a movie about terrorists, it must chose a discourse to permeate this movie and explain the motivations of said terrorists. Hollywood being a private venture, working on a profit basis, cannot chose a discourse that goes against his own interests. So they use the discourses (and the ruling class is not necessarely united in a single discourse) that best fit their interests or that at least dont put their interests at risk. This were the class program, being propagated by powerfull media entities, becomes a national program (gains cultural hegemony). The result is that other groups (a class is made of not only individuals but groups too) accept the political program of a group or class as if it was their own political program. Culture of the more powerfull reaches hegemony and becomes the national program on how to deal with terrorism (for one). So instead of dealing with the root problems that generates terrorism, USA goes on to apply military pressure on islamic countries (becouse the burgeoise of USA cannot solve that another way), wich can - for some time - solve the terrorism problem, but cannot preventing it from reappearing another day. This can be applied to various questions that USA are dealing today, and not only to the terrorism problem.