I dont know about the 'official' Army being only a Cadet myself but id assume that you have some sort of duty to disobey orders if they are A) a War crime B) Unlawful or C) Going against Conduct. I know from a friend of mine thats in the Austrian armed forces guard they have to alert a target that they will open fire if they dont stop what their doing. I'd assume that if an NCO or CO told you to do otherwise you dont do that as it goes against their code of conduct. I thought they would have some sort of rules after Vietnam anyways. 

Edit: "and NOT an insubordinate, unreliable person that disregards the ideals of others to force an overly idealistic mindset onto people actually using their brains and considering the long-term consequences of their actions." You understand that if you shoot an Innocent man on a Lieutenants orders you both will go away for a long time for war crimes. The minute you switch into that mindset your no better than many of Historys most vilified leaders.