pacifism by default?

I have been wondering a fair amount lately about the sanctity of human life and war. I am totally okay with killing the guilty-- God tells us that it's okay in Genesis 9 and then clarifies that the government has that power nowadays in Romans 13, and I don't feel like that needs to be any more complicated (though I am sure that some of my readers will disagree with me there.) However, the difficulty comes in considering the question of war because in nearly every war ever fought, innocent civilians die. Perhaps they are supporting the military, or perhaps not. If one nation is justified in going to war against another, perhaps the civilians on the immoral side are participating in something immoral and perhaps they are not. I don't think that's particularly relevant. The traditional position of most Christians seems to be that war and the death of civilians therein is justified because of some combination of "the-ends-justify-the-means" and the fact that civilians often die "unintentionally" in the pursuit of the higher cause. This latter fact is, I must admit, practiced admirably by most Western nations nowadays and is flagrantly violated by most of their enemies.

However, I would argue that this still doesn't really cut the mustard. I think it is clear in the Bible that God is meant to decide who lives and who dies, and He specifically extends that authority to humans on a very limited basis, and even then only specific people may die as the result of God-given human force. In every case, these are people determined by God to be guilty before Him. In the OT, this involved the nations around Israel who had been found wanting in their worship of idols; war against them by Israel was then a particular aspect of God's judgment against them and righteous solely because of God's command. In the NT, we see that the power of the state has been diminished only to "punish the guilty" when it comes to the use of the sword. Thus, there is absolutely no positive command in either the NT or the OT that allows for the killing of innocent people, in war or elsewhere.

What about the negative commands? Well, I don't think you have to look far for that. In the Ten Commandments, God tells us that murder is a sin against Him, and while there is certainly ample Biblical evidence that not all killing is murder, there is simply none that the death of an innocent falls into this category. We must also reckon with Jesus' words to us to love our enemies and not to return evil for evil. While I think that this does not entirely apply to nation-states, I think that this very clear command cannot be ignored except to our moral peril. We cannot evade the words of God with worldly wisdom that seeks to justify the actions taken for our safety or even for the ostensible safety of others.

It may seem tempting to say that it is "loving" to kill others that we might save more, but isn't this the same logic that applies to stem-cell research? God has never given the state the power to kill anyone but those who have already proved themselves guilty, and we should not presume to say otherwise.

This is has been batting around in my head for a while, and I wanted this post to be shorter in order to more adequately spark discussion, but I wanted to explain the reasoning that I run up against. Thoughts? Specific Biblical passages would be very helpful.