I used to find hope in this idea of going to another planet, so if we nuke one planet we're still okay as a species. But heck, if our species is inclined to wag

I used to find hope in this idea of going to another planet, so if we nuke one planet we're still okay as a species. But heck, if our species is inclined to wage destructive war on ourselves, we're probably going to do it a second time. We'd have to colonize a lot of planets to find the rare group of humans who would not resort to destructive power struggles. I'm not yet convinced that we're going to destroy ourselves, but it wouldn't surprise me to find that self-destruction is in our nature. To put some numbers on it, if humanity has a 25% chance of destroying itself within 1000 years of discovering nuclear power, how many planets do we need to colonize to have a reasonable chance of surviving another 10,000 years? (survival = no catastrophic nuclear event, survival != a subset of humans barely making it in a post-apocalyptic world)