The 6th Commandment tells us not to kill.....yet there is SO much killing in the Old Testament! One thing that God hates is the shedding of innocent blood yet you KNOW there must have been little babies and animals even. that were slaughtered simply because they got in the way.
You are right, it is sad. Today it has become to kill for your country and make war to defend your country, but there is nothing about defending God or making Peace as God says to do. Love your Neighbor, but instead people kill their neighbor. The wars in the old testament show clearly that God does not like war, those who even were thinking they were following God were punished, even sent to their own death because they lived by the sword and they died by the sword.
When Noah was attacked, God used an evil man to kill the other evil man, though the evil man who protected Noah and his sons was just better then the other, but he still died in the flood. God's vengeance perhaps. Noah and his sons survived.
There are also times when an entire Nation was so evil that God did allow the good armies to destroy them. God did say He would not destroy man after the flood anymore, so man would destroy man.
God may use such good people to defend what is right, that those who stand up for God and God's word will be victorious, even though I am sure God feels saddened by the killing and shedding of blood.
Why Governments send out troops to kill millions of others, even innocent people, use weapons of mass destruction upon entire masses of innocent people, have assassination lists for others and even for their own citizens is because that Government has no Christian values and has ignored God's Laws. It is important to vote in Christian leaders who will live by God's Laws.
God wiped out the entire earth once by a flood, just because there was so much war, evil and violence. The entire world turned against God and ignored God to live only by their own desires and they lived evil lives of war, gay sex, rape and violence.
That sodom was destroyed because it was a gay city, men were raped by other men on the streets, women were violated daily, and even when the angels went there the gays tried to have sex with the angels and the angels blinded the gay men. Sounds like the world today? Just about, in a few more years it will be.
Does God allow self defense? Of course, even the angels defended themselves. To kill? No. Mame or disable, even cut off an arm or leg, but try not to kill in self defense. Shoot them in the leg kind of thing.
To kill innocent children in the womb, I am sure God is angry and furious beyond anything I can imagine and I sure wouldn't want to be the one who gets punished for those crimes against God. It doesn't matter if it is rape that made her pregnant. The difference between rape and loving sex is only consent. The process of making a baby is the same. God says do not kill, but people do it anyway to exchange one sin against them for a bigger one against God.
It is sad. I Pray God comes soon. It breaks my heart to see this world the way it was before the flood. God is coming and He is angry. God Bless. Praise be the Lord Jesus! Bring us Justice to this world and take us home.