DKos Internal Poll: When is War necessary?

I'm keeping this one short, because more than anything I'm just damned curious. I want to know when you personally think War is morally acceptable. I think we can safely assume that it depends on when you think war is practically necessary, with no other option.

In these postmodern times, we hear two kinds of rhetoric in the leadup to a war. One is the World War 2 rhetoric, that the enemy is determined to inflict violence and they must be stopped. The other is the Vietnam War rhetoric, that the conflict is not necessary.

Inherent in that rhetorical one-side-versus-the-other battle is the underlying belief that war is morally gray, not black and white. Talking about taking life to save life is morally muddy, at best... and we navigate it by invoking "just wars" (WW2) and "unjust wars" (Nam).

We seldom hear politicians invoke the third view -- that it's never ethical to condone a war, and it's always better to abstain from war. In all those glorious videos about WW2, you seldom hear of what Gandhi was saying at the time. Passive resistance has rarely been considered an option against the Nazis, even in retrospect.

I know this is a divisive topic, but don't think I'm trying to provoke a flame war. I think we can have an intelligent discussion here.

Recommend it so we can get a wide variety of opinions. (?)

(I have a feeling there won't just be a flame war, but I'll get flamed for asking a divisive question. I really am just curious.)