While I was against the Vietnam war I do not believe all Veterans are natural born killers, with or without PTSD.  I just remember during the height of the Iraq war that a good percentage of the homeless were veterans, I think something like 25%.  Now a good percentage of them had mental problems such as PTSD.  I also remember a lot of them had cases of domestic violence, far above the general public.  

I have no grudge against war veterans.  I consider a lot of them to  be victims.  Between agent orange, DU, multiple deployments, it is a wonder any are left sane.  The government loves to say support our troops, but the help our troops get after they serve has been pretty poor.