Do the ends ever justify the means? Is it ever acceptable to do something wrong if it helps bring about a cause that is noble? Is it ethical to require a few to make painful sacrifices for the good of the majority?

These are questions all societies must ask during times of war, and the answers to these questions are rarely easy or clear-cut. "Ender's Game," a new movie based on a popular 1985 sci-fi book, explores some of these issues, as well the fall-out for those who have to make these difficult decisions.

In the future, the planet Earth is almost destroyed by an insect-like race of aliens known as Formics. To prepare for what humanity assumes will be the inevitable second invasion, the military begins training children to serve as commanders of the space fleet that will be used to fight the Formics. One of these children is Ender Wiggin. Lonely and bullied — but also a tactical genius — Ender is singled out as humanity's best hope for defending Earth from the Formics.

He is sent to "battle school" on a space station, where he is pushed through seemingly endless rounds of physical and psychological testing. The training will prepare him to lead Earth's forces, but how much of his innocence and humanity will he be required to give up?

One of the most fascinating things about "Ender's Game" is that the book feels perhaps even more relevant than when it was released in 1985. At first, it does takes a bit of a leap for viewers to buy into the fact the military would actually put children in command. However, the story's futuristic form of warfare is controlled in a way that's eerily similar to modern videogames, which today's children have grown up playing — and they are, admittedly, better at these games than many adults. As the film's voiceover states, children have quicker reflexes and haven't learned to be afraid to make risky, out-of-the-box tactical decisions.

Although the film has solid supporting actors — including Harrison Ford, Viola Davis and Ben Kingsley — the stars of the movie are its young (and refreshingly diverse) cast. Ender is played by Asa Butterfield, who is able to make the character both vulnerable and impenetrable. His icy blue eyes are intense and infinitely sad. He intentionally remains a bit of a puzzle, to both his adult trainers and the audience.

Hollywood long considered the book to be unfilmable, but I think the director Gavin Hood managed to pull it off. The film falls just a bit short of "epic," and I wish just a little more time would have been devoted to character development, to help us make a deeper emotional connection to the characters. However, it's still an intriguing, thought-provoking film, and the special effects — particularly the scenes with the glass-enclosed, zero-g battle room in space — are stunning. "Ender's Game" forces us to think about the choices we make during war, and what those choices cost us in the long run.