In "Soldier's Home," why is Krebs so dispassionate towards everything, including women?Ernest Hemingway

Krebs's horrific experiences in World War I have killed
something inside him; that is, his spirit has been destroyed by the war.  After the
senselessness of warfare, Krebs has little desire for anything; he just wants everything
to be simple as he attempts to reorder his life by reading about the war in an effort to
have guidance in understanding his experiences.

Because he
is so shocked by the savagery of war and the existential meaningless of life, Krebs
dislikes the complications of lying, which is what people seem to want whenever they ask
him questions. For, he has "acquired the nausea in regard to experience that is the
result of untruth or exaggeration."  Because of this nausea and because the young
girls

lived in
such a complicated world of already defined alliances and shifting feuds...Krebs did not
feel the energy or the courage to break into
it.

The appeal of the women
is "not very strong" since their lives are a small battleground themselves with their
"alliances" and "feuds." Krebs wants no part of the interpersonal and "political"
complications of dating or going with one woman.  He merely wants things to be simple as
it had been during the war with the French or the German girls; there were no emotional
attachments.  Emotional attachments are too difficult for Krebs now in his psychological
post-war confusion.  He even tells his mother when she asks if he lover her, "No." 
Krebs cannot be what he once was; the war has taken that person from
him.