4. Locke And Demosthenes
One major subplot of the book involves Ender's older siblings, the sadistic Peter and loving Valentine. At the age of 12, Peter convinces Valentine that the two of them should adopt pseudonyms and submit writings to the internet in an attempt to manipulate world events and opinions. Peter goes by the name of Locke, and Valentine by Demosthenes. In order to hide their true identities, their alter-egos exhibit completely opposite personalities of themselves. Demosthenes aims to stir up hostility toward governments, whereas Locke becomes the more empathic of the two, calling for communication and understanding between nations. The two play off of each others' writings and gradually gain a following, and slowly begin to shape public opinion about global events. When Ender defeats the Buggers, the world jumps right into war, as Peter had predicted. Now that the shadow of the Bugger threat is gone, countries like the US and Russia renew old conflicts. It's Peter who eventually ends the League War, which could have lasted years, in a mere five days. He does this through the "Locke Proposal," and uses his influence as Locke to eventually rule the entire world (more on that in a minute).
Why We Probably Won't See It In The Movie: A major subplot involving political espionage handled by blogging children may work in the book, but would be incredibly hard, and nearly impossible, to portray on screen. Such a big distraction from the main storyline would detract from any attachment we're supposed to feel for Ender, and will ultimately not be as important as his story. Maybe we'll see an easter egg, such as a character reading a Demosthenes article, or a mention of the Lock Proposal, but don't count on seeing their scheme play out in full. Which brings me to my next point...