Roger Ebert was asked a similar question at his 2003 "Overlooked Film Festival".
QUESTION: Hello, Mr. Ebert. I'm afraid that my question is a serious one. We are living in a very scary world right now. We are at war with Iraq, North Korea has nuclear weapons, and there are secret terrorist organizations all over the world who's only goal is to destroy us and destroy our way of life. It would seem that the movies are only a trivial thing at a time like this, but I think that they can actually be much more important. I was wondering what role you think films play in today's world, and if you think films really can change things for the better. -- Michael Guerena, Los Angeles, CA (18 yrs. old)
EBERT: Movies are an empathy machine. Better than any other art form, they allow us the sensation of standing in somebody else's shoes. We are trapped in ourselves, in our own box of space and time, and to identity with movie characters is a way to get outside of that box. No one familiar with the recent Iranian cinema, for example, could take a monolithic "axis of evil" view of that country. Good movies are civilizing, thoughtful, humanizing. Bad movies of course are another matter.
http://www.rottentomatoes.com/features/special/ebert/