In an objective sense it does make sense, although I can't imagine you would be alright with a soldier that killed innocent civilians by order of his superior and uses the Gita as his excuse. In my opinion there is always moral responsibility, no matter what you do or under who's order you do it.
You assume that the prescribed duty of a soldier is to kill civilians.
The BG on the duty of a soldier:
“Valour, glory, firmness, skill, generosity, steadiness in battle and ability to rule - these constitute the duty of a soldier. They flow from his own nature.”