Unless souls are saved, nothing is saved; there can be no world peace unless there is soul peace. World wars are only projections of the conflicts waged inside the souls of men and women, for nothing happens in the external world that has not first happened within a soul.
The pacifist thinks that the alternative to war is peace; it is not. Sometimes the alternative is oppression. Sometimes certain God-given rights and liberties can be preserved only by resistance to that which would destroy them. And to defend certain basic God-given rights and liberties is not immoral but righteous.
Calamity, war, famine, plague, death, adversity, disease, injury do not necessarily produce repentance. We may become better in a calamity but it does not necessarily make us repent. The essence of repentance is that we cannot be repentant until we confront our own self righteousness with God's righteousness.
The industrial and social injustice of our era is the tragic aftermath of democracy's overemphasis on freedom as the "right to do whatever you please." No, freedom means the right to do what you ought, and ought implies law, and law implies justice, and justice implies God. So too in war, a nation that fights for freedom divorced from justice has no right to war, because it does not know why it wants to be free, or why it wants anyone else to be free.
Wars come from egotism and selfishness. Every macrocosmic or world war has its origin in microcosmic wars going on inside millions and millions of individuals.