If you mean by Sabbath to rest on Saturday then I would say that would be highly unlikely. I'm not, not have never been, in the army but I'm sure you would have to be ready on any day of the week in case trouble comes your way. The Macabees likewise took rest on the Sabbath when they were getting attacked by the Romans and they were killed.
God will understand if you're working on the Sabbath to protect your country, less we end up like the Macabees. David ate holy bread which he wasn't allowed to, but God understood because he needed the bread to eat.

My ex actually found God while she was at boot camp, I proud of her guess dragging her to church helped. You can still go to church even in boot camp.