Social Construction of Killing

I would like to further expand upon the thought process I was trying to articulate today in class about what I consider to be the social construction of our understanding of "killing." When I shoot someone in Memphis, that is "murder." When I pull the same trigger in Iraq (iffy example, I realize), it's an "act of war." The same action goes by two different names, and the same action receives two different reactions from both the public arena and from the judicial system. I can receive a death sentence for one and I can receive a medal for the other. I understand that these two scenarios fall under different legal categories based on the definitions we have constructed of what constitutes "murder" qua "murder," but viewing the action through a Kantian lens, it seems as though the actions are not so different. We cannot say that as a universal maxim, killing is to be praised. Therefore, it cannot be. Regardless of whether it's Osama bin Laden or whoever we deem to be the manifestation of pure evil or whatever, we cannot celebrate death as a universal maxim. I think this is what Dr. Krog was talking about, in a way, because when we begin to permit or even celebrate some murders, where is the line? When does it stop?