Stephen L. Carter examines the case for “humanitarian” war:
[M]ost of us agree that war is morally permissible to defend one’s own country against aggression. There are difficult questions still. (What counts as aggression? May one attack before the enemy strikes?) But wide consensus exists on the general principle of self-defense.
The more difficult question, and one that increasingly confronts the world, is the justice of going to war to protect not our own people but someone else’s. In other words, if Christian morality will permit Country A to fight Country B if Country B attacks it, will it allow Country A to fight Country B if Country B attacks Country C? Or what if Country B is slaughtering only its own people? May Country A go to war to protect the people of Country B against their own government? […]
Indeed, one might argue that there is a provincialism, if not selfishness, in saying that it is moral for me to defend my own people but not someone else’s. In much the same way, my right to defend myself against an attacker on the street also gives me the right to defend the fellow next to me.
I am not offering a settled answer to this question. The literature of just-war theory is strongly divided on many issues. I insist on two propositions, however. First, the morality of humanitarian intervention has nothing to do with whether others agree that the action is appropriate. (Although, as I have noted, international opposition might render it impractical.) Second, to refuse to protect the people of another country simply because they are not fellow citizens is, to say the least, uncharitable.
I think many thinkers in the just-war tradition would agree with Carter here. Paul Ramsey held, for example, that the legitimate use of force was nothing more or less than the expression of neighbor-love in the political realm. If I am called to help the man in distress by the side of the Jericho Road, would I not also be called to use force to repel the robbers if I came upon them in the act? And it’s hard to see why, on Christian grounds, this obligation should be limited to our fellow citizens. There may be, as Carter points out, practical reasons not to intervene, but not necessarily moral ones.
However, just-war theory (as this blog has discussed before) requires several other conditions to be met for any prima facie case for third-party intervention to carry the day. Prospect of success and proportionality are key here (i.e. will war stop a greater evil than it will bring in its wake?), as is discrimination or immunity of non-combatants.
Even more troubling to me (see here) is the question of whether the modern secular nation-state can be relied upon to restrain itself in warfare and to act according to just-war principles. Though just-war theory has gained wide currency in secular thought (see Walzer most prominently), it retains its roots in Christian ethics. And history shows us that the dictates of “realism” tend to hold sway over just-war scruples whenever the going gets rough and victory is on the line (WWII is the classic example here).
If the secular state refuses to place itself under those constraints, then I have a difficult time seeing how a Christian can be anything other than a de facto pacifist, refusing to endorse or support any wars. I’m not comfortable with this position, but it may be that just-war principles only have bite if the state itself is explicitly committed to them.