1. what is the major theme of this novel? why is this theme important to a teenager living in 2007?

Compassion is the theme that runs through Ender’s Game. This word defines of his existence. Compassion saves Ender from fighting against the enemies. If not for his compassion, he would have become either a killer or a person like Peter who wants power. By Ender showing compassion to the buggers, he destroyed the buggers’ race by giving them a chance to start new. Graff’s and Valentine’s compassion helps Ender from despair. Even later, Mazer Rackham shows that he is capable of showing compassion. Finally, the buggers demonstrate compassion to Ender, and this convinces him that he must make it his mission to see that their queen is found a safe home to start new. Compassion provides hope for the future.
Ruthlessness is sometimes necessary but it is something to be avoided. Only Peter is ruthless, and the danger of influence without conscience comes out from the inside of him. Peter is able to gain what he wants because he does not care about others, and he will never stop. Ruthlessness is the human condition devoid of its humanity, and it is the danger that threatens total destruction.
In Ender's Game it is never entirely clear who is a friend and who is an enemy. Graff, Anderson, and Rackham, who are undoubtedly Ender’s friends, appear to Ender as enemies and are forced to do so.