According to Advaitic/Yogic sages, all sins and atrocities which are committed by individuals and nations against each other are due to ignorance of the true nature of oneness of all life.
When we view “others” as separate from us and different, we are able to justify all types of ignoble acts against them. Sometimes, even the most heinous deeds are justified in the name of God, religion, or law.
People who are blinded by fear, greed, and ignorance are not able to see outside the cycle of violence that they are part of.
Fortunately, in the history of the world, there have always been good people as well and such noble souls still walk the earth today. I feel that due to their kindness, love, and compassionate influence, there is always a ray of sunshine and a hope to make this world a better place.