I'm a little lost one of my wifes co-workers is going back into the military.
And he said he's a Conscientious Objectors.

To me that would be like a Vegetarian working in a slaughterhouse

Can anyone explain? I know there is no draft so it's not like they are being forced to fight.

Well, there are a lot of reasons that one can claim "conscientious objector" status. It can be related to a specific war rather than to all war in general. So my guesss (and it's only a guess) is that your wife's co-worker is not a pacifist. He probably believes that some war is justified, but he is objecting to the US involvement in this particular war (Iraq).

It's allowed - you can serve in a non-combat status and position. Chances are - you won't be running anything big. . . .