I have long felt sorry for Cain. He tried so hard to get it right! God was supposedly disappointed that he didn't deliver a blood sacrifice by killing a living being. So to please God, he thought nothing could be a bigger sacrifice than to shed the blood of his own dear brother, and then he did so! But even after that, God still wasn't happy with him. Poor Cain. Now he had two things to feel terrible about; God's unhappiness with him, and having to go on living without his dear brother.It's much bigger than politics.
There has been distrust and at times strife between the nomadic and settled populations.
The Bible's Cain and Abel is a great example. The moral of that story was that agrarians with their wheat were wasting their time. The nomadic shepherds with their animals were more important!
Some anthropologists and archeologists like to pin the start of civilization to the switch from nomadic to settled agrarianism.
Though the discovery of the 11-15k year old buried structures at Gobekeli Tepe upset that timeline a bit.
There is a fictional movie about Cain I have watched several times and intend to watch again. It's titled He Never Died. Spoiler alert: You don't find out until near the end of the movie that this guy is actually Cain; his punishment from God having been that unlike his brother Abel, he can never be killed, by anyone, or by any means.