In Denis Johnson's novel "Train Dreams," the idea of coexistence with nature is explored, particularly through the metaphor of a tree. The quote suggests that when a tree is left undisturbed, it can become an ally, symbolizing the harmony that comes from allowing nature to thrive without interference. It implies that respect for nature leads to a peaceful relationship, emphasizing the importance of observing and appreciating the natural world as opposed to exploiting it.

On the contrary, the quote highlights that when human interference occurs, such as cutting down a tree, it results in conflict and destruction—a 'war' between humanity and nature. This reflects the broader theme of the novel, which grapples with the consequences of industrialization and the loss of the natural environment. Johnson’s work poignantly illustrates how our actions can provoke adversarial relationships with the very world that we depend on for survival.