mik, this has been ask and answered a millions times for a million different people, including and especially, one Sgt. Alvin York during the first world war.
The commandment says specifically: "Thou shalt not kill"
Now the literal meaning is obvious, but the taking of life in war held in a much different light than murder. One would think that you would know this from your time in the military.
Remember, after giving this commandment, God aided the Hebrews in a campaign to retake the lands given by God to Abraham, father of the Jewish race, after their centuries long bondage in Egypt.
Before I get pounded on it:
Yes, I know Abraham is also the Father of the Arab race. However, he fathered Ishmael with a servant girl, due to a lack of faith in God, who said that his 90 year old wife, Sarah, would bear him a son. Ishmael and his mother were subsequently turned out of the camp when Sarah became pregnant at the ripe old age of 98, IIRC.