He got injured before he saw combat and had a Long convalescent period, so there definitely is a bit of a chip on his shoulder with respect to honor cultures and willingness to fight.

my step grandfather was stationed in military intelligence rather than fighting on the front lines in the war. he felt like it separated him from the folk at the vfw and that self-imposed separation was the root of his ptsd. mom and dad had us read heinlein, i realized a lot later as a way to try to understand him and his brokenness.