SB,
The article that you provided gives situations where soldiers can disobey their superiors if the orders are unreasonable. - But how many soldiers get that opportunity to scrutinize their conscience while in the field?
Also, isn't war fuelled by state propaganda? A Russian Christian soldier will mercilessly hit a shopping complex in Ukraine because he is convinced in his heart that Ukrainians are his enemies. I'm not sure if his Christian conscience will be in bearing for his actions.
In India, many Christian soldiers were part of the contingent that participated in Operation Blue Star in 1984. However, many experts still believe that the operation was a political move by the local government, and was utterly unnecessary.
In short, Doesn't a Christian soldier participate in war in a zest of patriotic fervor and the propaganda fed to him by the ruling party? I'm not sure if his Christian ideologies will come into play on the battlefield.