I certainly wouldn't bet my first born on that statement. I think there's a perception (possibly quite accurate) that extreme stress is more prevalent among soldiers, marines etc. than among waitresses!
I don't know the answer to the following, but it's worth asking. How does the extreme stress of the soldier compare to the prolonged stress of his children.
The soldier's stress might be short-lived,let's say the few-years duration of a war. Even ten years would be short'lived compared to what I'll mention below.
Now his child might be emotionally or otherwise abused by his father as a result of his father's PTSD perhaps from birth right up until he leaves home at 18.
The father might have the advantage of having developed a healthy mind prior to going to war. The child has no such benefit, no alternative experiential point of reference, that stress being the norm for him. While the father might be aware of how the war changed him the child has no experience of a trauma-free past.
Of course there are simplification here. If his grandfather also suffered PTSD, then his father might also have been raised in a traumatic environment. Being raised suffering from Transgenerational trauma and then going off to war himself would likely exacerbate the trauma. But worse yet, that father might not recognize the symptoms since he would have been raised with PTSD himself,making it even worse for his child.
Then when we consider the WWI and WWII and Korean War, the Balkans, Somalia, Afghanistan generations, we can ask ourselves, how many Canadians might suffer transgenerational trauma at the hands of PTSD-ridden parents, and how might that have affected our culture generally, at least with regards to addiction and mental health issues.