If your pursuits to find the truth have been at all successful, I could go about my life as I have been, and you would share the truth you worked so hard to uncover with the world. Alas, your devotion and willingness to sacrifice your life for the truth have proven to be fruitless thus far, so here I am, just like you, sitting without knowledge of any of these truths, so despite your being overcome with the burden to find the truth, you found no truth, and nor have I. It's as if you walked in a hundred mile loop to get to your friends house while I simply walked across the street.
There are people in this world who I like to refer to as sharks. Predators. Sharks have always existed everywhere there was ever man. A shark is anyone who is willing to take unethical measures for the betterment of their own self interests. Somebody, for instance, who will lie, cheat or steal. Here's the problem. A good man who is not a shark, if intelligent, will understand that sharks do exist and that to live safely amongst them, one must occasionally adjust their own behavior.
The idea of sharks exists in game theory. For instance, in some scenarios a good man is driven towards making a selfish decision seemingly against his instincts, simply because he understands that somebody else involved may be a shark, in which case he will be harmed by making the decision he seems to be the more ethical of the two. The Dark Knight ferry scene was a great example of this.
People who say that war is part of human nature are correct in a way, but the concept is greatly misunderstood. Some humans are indeed built for starting wars, others are built to fight them. Some are not built for this sort of thing at all. At the very core of all wars lies a fundamental truth. Somebody wants something and somebody else does not want them to have that thing. The thing can be anything and pops up in different forms throughout history.
If you go way back in time, to Paleolithic man, war would have been excruciatingly simple, but fundamentally the same. Someone wants the hoard of fish you just took in so he tries to take it. You ask him nicely not to take it and he grabs it from you. You ask him to give it back. He lets out a screech. You try to grab it and he inches closer to you, looking you in the eyes. You push him. He punches you in the face and begins kicking you when you're down. You free yourself from his grasp and he comes after you again. So you grab a piece of flint and stab it through his chest.
Some time later, man has banded into communities with hundreds of members. Then they settled and started forming small city states. Then other city states would want their gold so they would take it. Then the one city state would ask the other not to take it, but they would take it anyway. Then the bronze comes out and finds its way into somebody's chest.
There's no other way around it. No way to get the mythical world peace. It is just not possible. This is not saying I believe that wars are all just or that I agree with any of them at all. It is just addressing the idea of world peace even being a possibility worth discussing.
Everybody in the world could agree upon world peace. It could be enacted. But them some shark would see an opportunity. And he would take it. And they would ask him nicely to stop and then another shark would see an opportunity somewhere else. He would take it. Pretty soon the world has to adjust its ways to deal with the persisting existence of the sharks.
What happens in a peaceful world when a rogue nation forms, arms itself, and begins taking resources from other regions for their own gain? Presumably the peace police come in and ask very nicely to stop. But then one of the bad guys shoots at the peace police. Fuck. If they shoot back, they aren't the peace police anymore, so they don't shoot. The bad guys take over the entire world this way, and that's how you end world peace in three days.