Rag, it has always been understood as "do no murder" since Moses.
The Israelites were constantly at war.

There is no indication in the New Testament that it is unjust, immoral, or inappropriate for secular civil governments to execute those guilty of shedding innocent blood.[52]

Like the Old Testament, the New Testament seems to depict the lawful use of force by soldiers in legitimate battles as justified.[53] The profession of soldier is used as a metaphor by Paul exhorting the Ephesians to "put on the full armor of God."[54] Cornelius, the Roman centurion, is portrayed as a righteous and God-fearing man.[55] Jesus praises the faith of a Roman centurion on the occasion of healing the centurion's servant, and states that he has not found such great faith even in Israel.[56] When John the Baptist was preaching repentance and baptizing penitent sinners in the Jordan river, soldiers came to John and asked for specific instructions regarding their repentance.John the Baptist did not demand that the soldiers renounce their profession, instead he exhorted them to be content with their pay.