In a world society with nearly 8 billion people how can there ever be such a thing as peace or harmony? This is one of the questions humanity is going to be facing in the next century. It's becoming increasingly clear that we can't really afford another World War with human lives at stake, so that leaves us with two options:
One suggestion I've heard to implement the latter method would be using purely automated machine armies of drones and robots. When one side loses their robots, they would have to give up. In a world where more and more information is publicly available and causing death of any sort becomes increasingly politically disadvantageous, the side which lost its robots would have to concede.
Of course, creating autonomous robots in the first place could potentially lead to issues of its own...
But do we really want to be caught in this cycle perpetually? I cannot help but believe that there is a better path forward, if only we are willing to think. Reflection, observation, and experimentation are not to be underestimated in the face of any problem. If such a process enabled space flight and blockchain, why would social problems of any sort be immune to it?