Olympus Has Fallen is an anti-terrorist action film on par with the best of the Die Hard films, or Air Force One. This would be a great film had it not gotten a little corny toward the end. The movie began to lose believability for me when they could not turn off a system that would destroy all our nuclear missiles.
There are many places in this movie where you probably don't want to think too hard. Despite the obvious problems with believability, the movie is fine. It is a great action film.