The human race hasn't had a single year of global peace ever. I looked it up. War is our default mode. Same with crime and disease. When you have laws, you'll always then have crime as not everyone's on board with subjugating their will to a government's. And when you have lots of people forced to live in close proximity you'll get diseases as some built-in mechanism seeks to thin out the numbers and some disease springs into being.
We are primates and predators. We naturally seek both community-living, but as predators competition, usually against our own best interests as with wroking more collectively. This contrary nature is one of the things that makes humans different from other animals, even other primates. Where other species exist harmoniously in nature, with nature, our species destroys nature and poisons it. No other animal destroys its' own habitat. That's all our's. And while many other species have the equivilent of war, crime, and interspecies conflict and violence, humans remain the only one who've gone from being able to kill others with a club, to destroying the entire planet's biosphere.