If the glue that holds the societies together was created by people with a minimum requirement for their human qualities and it became a requirement that elected officials should have/contain abilities in empathy, reason, honesty and humanity in order to be able to stand for public office, then maybe we could have a world society where there was room for everyone. Similarly, harmful traits such as power misery, lies, deception should be tested and this should lead to exclusion from all elected offices. In the more ideal world, more positive tones would spread and unite humanity for the good of all. This contrasts with the many eerie future-descriptive films with all sorts of versions of war and oppression. Let us shame their fictions and form the ideal world order where we maintain faith in life and replace the many faiths with the knowledge that it is good faith in something and that we must respect the faith of others.
Since the world is what we make of it, the UN is probably the closest we can get to global leadership, but it will take some more muscle and more reason for the UN to be more than fiction. If we raise the level of knowledge worldwide and create a more equitable distribution of the earth's resources, we will at the same time make many other problems disappear.