PTSD or Guilt?

"A king may move a man. A father may claim a son. But even if the men who move you be kings or men of great power, your soul is in your keeping alone. When you stand before God you cannot say 'But I was told to do thus' or that 'Virtue was not convenient at the time.' That will not suffice. Remember that."
--King Baldwin IV (Kingdom of Heaven)

In his review of the recently released film American Sniper, Jacob Hornberger wonders whether soldiers returning from armed combat truly suffer from post traumatic stress syndrome (PTSD) as commonly diagnosed. Or is it simply guilt?

God's law against wrongful killing is clear.  There are no exceptions for "following orders."

Individuals who kill others in wars of aggression must forever battle their consciences that they have done the supreme wrong. They have applied offensive, not defensive, force in lethal measures.

Despite the volumes of propaganda or rationalization that might stream through it, consciences are difficult to fool.