Analogy in a video

https://youtu.be/yRmOWcWdQAo?si=nJI4m7CJf8sW45y4 in this video he mentions an analogy about killing a neighbour because you know they'll kill you first. Although this relates to the video in question, I'm wondering whether the was an analogy he made up or one that already existed. If it's the latter please let me know. Much appreciated.

I know this isn't history based, but it's the only place I've seen with this analogy, and I'll like to know if this is the origin.