How do the events at the tree teach the reader about war and peace in the lives of the boys at Devon?

THey teach us that war and peace are a precarious thing. Gene and Finny are the best of friends but there still exists an underlying rivalry and discontent. There are no perfect relationships between people or countries. Finny's "Super Suicide Society" is an extension of their often dysfunctional friendship. Even at the best of times there are undercurrents of conflict (war) in their friendship.