In A Separate Peace, what does the war symbolize?Why is the symbol of war significant to the story?

The war is symbolic of the end of innoncence  Although the
boys spend much of their time at Devon preparing for the war, their lives remain rather
sheltered and detached from the reality that they will actually have to fight.  Finny
even goes as far as to say the war isn't even real.  This shows he is rebelling against
the idea of growing up and facing the real world. When characters, such as Leper, get
sent off to war, we see a sudden end of innocence, as they get exposed to the atrocities
that war presents.