There are two books of collected essays in the series, "Ender's Game and Philosophy". Many of the essays wrestle with applying Just War Theory to the plot of Ender's Game.
In the arguments, there were several points which weren't made, so there's now a supplementary essay available on the use of Foils in Ender's Game.Someday 2005-02-27
Ender's Game - The Original by Orson Scott Card
Ender's Game - The Cinematographic Interpretation
Ender is an exceptional child. He's also the result of genetic manipulation, as are his older brother (Peter) and sister (Valentine). All three were created in order to outsmart the aliens attacking Earth (yup, aliens). Peter turned out to be completely ruthless and devoid of compassion, while Valentine grew too understanding to be an effective combatant. Ender was the perfect mix of the two.
Split from his family at a young age by the government, Ender was sent to Battle School (along with other enhanced children) to learn how to be effective fighters. The rest of the story follows Ender through school and into war.
When you fight, what do you fight with? Everything and anything. While the content is fairly brutal (children rationally killing children), I think they'll be able to make a PG-13 film out of it. Regardless, the book was pure fun to read, especially if it makes you think about Defense in Depth and threat analysis.
Finally, the chronological order of the series is:
To talk about the ideas in the book, let's pull a Tolkien and assume that just like hobbits aren't actually hobbits, the space camp kids in Ender's Game aren't actually kids. So which ideas keep recurring?
Both story arcs of Ender and Valentine/Peter follow this tenet: "If you can't find your enemy, you can't fight them; if you can't undertand your enemy, you can't beat them." Peter sees that his persuasive skills need work, so he binds Valentine to himself until he no longer needs her. He also keeps the world blind to his identity until he's ready.
Ender sees others who are blind to their own issues, e.g. Bonzo and his pride, commanders using formations and the hook, Rose and his assumption of eventual success, Graff and "the computer" he doesn't understand. And throughout, as excellently as Ender understands the games he plays, he does not see the big picture and ends up being shipped off into the depths of space.
Loss / Torture
Peter tortures Ender and Valentine; at space school the teachers torture Ender and let other kids join in. Ender loses Valentine when he's move to space camp, and he loses his friends as he becomes an exceptional commander. Meanwhile, running the school takes its toll on Graff, and Mazer Rackham had to leave his family forever behind, just as Ender did.
Peter's parents believe that playing online keeps him from torturing little animals. Valentine believes that helping Peter play online will keep him from killing her. Ender plays the fantasy game to keep from thinking about the crap the school offers, and the rest of the time, he plays the school game, which keeps him from thinking about the larger world below him.
Peter is the only person not playing a diversionary game. Consider that maybe Peter wasn't lying when he said that the torture was an act, that he really was sorry the night before Ender left for space camp, and that maybe Peter flunked out of the program on purpose.
"If buggers didn't exist, it would have been necessary to invent them."