Slaughterhouse 5 - promotion of war through media

In this novel(p14), Mary O'Hare makes some statements about war movies and how they glorify and encourage wars in real life. I agree with her ideas. It seems evident, in movies like "Braveheart" and "Independence Day" that war, though disturbing at times, can make everyone a hero.
Some examples of scenes that support this idea are when William Wallace is beheaded at the end of Braveheart and the part of Independence Day when one man makes a kamikazee-like attack on the alien ship to stop it from blowing up New York City. I realize that this will not influence an entire country to decide to go to war, but rather individuals, who grow up watching these movies.
Also, I believe that even if a movie can be considered anti-war, it still can not possibly do the brutality and carnage of actually fighting in a war any justice.