Good thing Unobtainium isn't real.

The destruction of Hometree is the inciting incident of Avatar. It is the perfect representation of how one culture can destroy another cultures way of life and livelihood just like various wars in this history of humans. I am not focusing on this entire scene, however I am focusing on the exact moment when the large battle cruiser and smaller air ships descend from the sky and the Navi first see them coming.

When I saw this I realized what the scene was really depicting. In this scene we see an advanced version of our own race, flying in huge machinery towards a race of beings with no technology to speak of and live in the nature of their own planet. These humans, and mostly their airships, are so far advanced from what we have currently that when I saw this scene all the sudden they were the aliens. They were far enough ahead that I could see the same thing happening to us, even though they are "us". The movie did an excellent job of separating those humans from us just enough, that we were able to see them as the aliens, and in turn, ourselves. They force the viewer to recognize this with the scene of the people in the control room's reactions to the destruction, however it is still very clear even without taking that scene into account. All of this causes the viewer to suddenly have empathy for all of the cultures on Earth that have been destroyed by other cultures. This transfers very well to all of the stories in history text books, since most people probably haven't actually thought that hard about what it would have been like for a horde of horses to overrun your village, or a ship full of people coming across an ocean with guns. This is what the movie was going for, showing how our own race has fought against itself by showing a future version of ourselves fighting aliens in a future setting. This argument is against what various factions of the human race has been doing for years, and by the setting of the movie is implying that we haven't changed, aren't changing and in the future will not change. Later in the movie this is shown by Jake connecting to the tree and saying to look into Sigourney Weaver's characters memories about the humans (us) and what we have done to our planet.