There is mention of humans going underground and fighting with whatever means they have, including a guerilla-style warfare, If I recall correctly.
I will have to see the movie myself, but her description makes it sound like that is not the case in this movie, that there is no underground warfare because Cruise kills the Robbins character who wants to do that.
I believe the original premise of the book was that no matter how powerful we think we are, there's always going to be someone bigger. His ultimate irony was that the bigger, stronger, smarter enemy was brought down by the smallest among us.
Anyone see Lord of the Rings?
(Denny Crane: "Sometimes you can only look for answers from God and failing that... and Fox News".)