I first saw this film when I first really got into anime in High School. I'd grow up with Naussica and cartoons, and had just seen Akira, then my brother and I rented this.
We sat through the whole thing without saying a word, then when the movie was over we didn't even talk.
Not a simple film. Instead of just making the Americans out to be bad guys, the Japanese people in the children's village either through greed (their aunt) or through indifference (Gardener, Doctor), also play their part in the children's starvation and death. So it's not just about war, or anti-war, though I can't think a better movie to watch about war.
The animation is perfect also. Absolutely beautiful colors.
As another testament to the power of this movie, I decided to sponser a child through Compassion after watching it for the second time, 8 years later.
Everyone should see this one, but be warned, it's not Akira or even a Miyazaki movie. Watch it with an open mind and heart.