Which goes right back to "Oh, you like murdering dozens of people for zero reason? That's fine, it's all the same!" Bleh.
Killing an enemy soldier in combat is war, kill of be killed. It's fair game there. I would argue the same of Stand Your Ground laws, at least in theory. And we, as humans, have decided to grant the Government the ability to make moral judgments. The problem with a random guy killing someone is that he has no objectivity. See Kain's relative example above. Maybe your brother was a total douche and deserved to die, but you loved him, so you go off and kill his killer. That's shortsighted, subjective revenge. In America at least, we have a court system with judges and juries to mete out justice, which is much more objective.
Ok, what?
Seriously, all I was trying to say is that morality is subjective and entirely depends on the person. Like I said, I view killing as a fact of life, which is pretty much what you just supported, intentionally or not. I don't like killing, but I don't see it as being evil. It all depends on the situation, which supports why I think the 'sanctity of life' is BS, as I've already mentioned. You obviously have a different view on killing than me, hence your morals can be considered to be different from mine.
Plus, saying that a soldier killing another soldier in combat or someone defending themselves under the Stand You Ground laws is objective compared to a random person killing another is wrong. Soldiers are out to fight and survive, the latter automatically nullifying the objectivity you appear to claim. Someone defending themselves under the Stand Your Ground laws is subjective too. In fact, all forms of killing could be considered subjective.
As for the government, in a democracy, people can vote on most things, as you know. Saying that someone suffering the death penalty is objective is subjective due to the fact that the government views the person's crime(s) as deserving it, hence, it is not objective. Saying that something is subjective doesn't mean it doesn't exist. It just means that it's perception may vary from person to person.