"We were not destined to survive. The fact is, we were not destined at all. The war would take what it could get. It was patient. It didn't care about objectives, or boundaries, whether you were loved by many or not at all. While I slept that summer, the war came to me in my dreams and showed me its sole purpose: to go on, only to go on. And I knew the war would have its way." 

This passage, from the very first pages of the novel, establishes Bart's narratorial voice, including the reflective and almost philosophical turns it sometimes takes. Bart, as a retrospective narrator, looking back on these events at least five years after the fact, is able to imbue this initial section with an almost cosmic perspective. Bart dismisses fate as a major factor in the events he is narrating, and also personifies the war itself, giving it a sort of evolutionary drive to survive and continue to exist. This idea of the perpetual motion of the war comes back up later in the novel, in Chapter 4, when Sterling mentions that the army has retaken Al Tafar twice already, prompting Bart and Murph to both think about the conflict as being as inevitable as the seasons.

"War is the great maker of solipsists: how are you going to save my life today? Dying would be one way. If you die, it becomes more likely that I will not. You're nothing, that's the secret: a uniform in a sea of numbers, a number in a sea of dust." 

Solipsism is the belief that the self is the only thing that can truly be known, and everything else in the universe could be a figment of one's own imagination for all one knows, leading to a literal self-centeredness. Bart and Murph obsess over, and take comfort in, the number of U.S. soldiers dead remaining under 1,000.