The New Message: Humanity will destroy itself by wasting time on science and medicine instead of building weapons.
There have been approximately 8,000 sequels, spinoffs, and reboots of Planet Of The Apes, ranging in quality from "fine" to "horribad". But we'd like to focus on the most recent iteration: the well-regarded Rise Of The Dawn Of The War For The Planet Of The Apes.
The first movie, Rise, is a gritty reboot which shows us how the human planet becomes the ape planet. There's no massive nuclear war, followed by the slow, centuries-long ascent of ape here -- instead, a botched medical experiment grants apes intelligence while killing off the vast majority of humanity. Was it an attempt to create some sort of hideous biological weapon? Nope, James Franco wanted to cure his father's Alzheimer's. Humanity isn't doomed by the thoughtless pursuit of warmongering violence, but by the pursuit of medicine that would better the world. Hope you ... learned your lesson?
20th Century Fox
That'll teach you to help people with degenerative diseases!
Then, in Dawn, ape leader Caesar learns about how useful violence is, which is exactly the opposite of the original point. For most of the movie, he's a firm adherent of the philosophy that "ape shall not kill ape." But after one of his followers, Koba, conducts an elaborate false flag operation to trick the apes into starting a war with the smart, resourceful, and (mostly) peaceful humans, Caesar decides he was naive for believing that apes were superior to man and kills Koba. The next film in the series, War For The Planet Of The Apes, will be about precisely what the title promises, but it's a war that's 100 percent the apes' fault -- humanity is still awesome. Our only crime was caring too much. And not making enough weapons to defeat the monkeys.