Just began reading Karl Marlantes’ What it is Like to go to War (Atlantic Monthly Press, 2011). If you have loved ones who have served in combat I highly recommend you read this to understand a bit of their experiences. Karl Marlantes is a veteran of the Vietnam War and in this book details the 
spiritual and psychological impact of killing and combat. While his view of God would vary from most Christians, I think most believers will find his descriptions of war’s destruction on a person very accurate.
Marlantes considers the spiritual nature of war,
Many will argue that there is nothing remotely spiritual in combat. Consider this. Mystical or religious experiences have four common components: constant awareness of one’s own inevitable death, total focus on the present moment, the valuing of other people’s lives above one’s own, and being part of a larger religious community such as the Sangha, ummah, or church. All four of these exist in combat.
Most of us, including me, would prefer to think of a sacred space as some light-filled wondrous place where we can feel good and find a way to shore up our psyches against death. We don’t want to think that something as ugly and brutal as combat could be involved in any way with the spiritual. However, would any practicing Christian say that Calvary Hill was not a sacred space? (p. 7-8)
Just prior to this quote he tells of a harrowing experience where he was in charge of a small band of men defending US interests with no opportunity for backup. Decisions he made led to the deaths of enemies and fellow marines. In a break in the action, a chaplain was flown in bringing, “several bottles of Southern Comfort and some new dirty jokes.” (p. 7) He tells how this “help” wasn’t what he really needed,
I felt responsible for the lives and deaths of my companions. I was struggling with a situation approaching the sacred in it terror and contact with the infinite, and he was trying to numb me to it. I needed help with the existential terror of my own death and responsibility for the death of others, enemies and friends, not Southern Comfort. I needed a spiritual guide. (p. 7)
Consider the book if you live with, love, or work with a veteran of combat.
Musings on Faith and Psychology 
Thank you so much for this post. Am I the only one who now wants to be a military chaplain? So sad that a person being paid to be a “spiritual guide” is unable (or unwilling) to bring the comfort of the Lord in the face of trauma.
Can reading a book about “what is it like” be enough to cause trauma to someone who is already emotionally triggered by the subject because of having a loved one who is active military?