At the beginning of Chapter 9, there is "a separate peace" created within Gene, who is deceived by his own happiness because
...surrounding world confusion found no reflection inside me. So I ceased to have any real sense of it.
Likewise, Leper Lepellier senses no real war. Leper is absorbed in only "his snails and beaver dams"; he has slept on the top of Mount Katahdin in Maine, the point where the rising sun first strikes American territory. So, when a recruiter from the United States ski troops comes to the school and shows a film to the seniors which depicts troopers in pure white, "silent as angels," with the cleanest image of war that Gene can imagine, Leper becomes enthralled,
...this cool, clen response to war glided straight into Leper's Vermont heart.
He concludes at the end of the film that the swift skiers are proof of nature's survival of the fittest. He, therefore, fits the war into his interest in nature,
"I'm almost glad this war came along. It's like a test, isn't it, and only the things and the people who've been evolving the right way survive."
The war, then, becomes for Leper an experiment in natural selection; for it, like everything "has to evolve or else it perishes," he says.