People will give their lives to save others. People will kill to defend their ideas and beliefs. This is true of the jihadist pressing the detonator and the rioter swinging a bat. This is true of the person yelling at their spouse over a disagreement about where to eat, yelling in hopes of killing the other person's heart and soul.
Divorce and wars are often instigated not by financial stress or disputed resources, but by the disparate beliefs and values in the hearts of people.
In most people there is generally no taste for reason and logic, and certainly not critical thinking. Manipulation by others casts and solidifies their beliefs and values. Only trauma and abject defeat can undo the spell.
Since the 1980s, the forces of good, justice, liberty, and democracy have slowly but surely been losing this war for minds. Then came the internet, the equivalent of nuclear weapons in the war of social manipulation, and the perfect opportunity for despots worldwide to find, connect with, and enrage their scattered bloodthirsty mobs. The war, the real war, fought in the hearts and minds of the populace, is over. Evil and fear have again seduced that critical mass, not a majority of the populace, but enough of those with a propensity for violence. We must now endure the formality of that violence and warfare that will officially seal the victory.