The principle of absolute sovereignty may have been consigned to history, but a strong presumption against foreign intervention seems to have been left in its stead. On the dominant view, only massacre and ethnic cleansing justify armed intervention, these harms must be already occurring or...

If pacifists are correct in thinking that war is always unjust, then presumably we ought to eliminate the possibility and temptation of ever engaging in it; we should not build war-making capacity, and if we already have, then demilitarization—or military abolition—would seem to be the...