Who believed that the best way to avoid a third world war was to create a new world order that all nations had the right of self determination?

The NWO has nothing to do with self determination of the nations. Global governance is the framework into which the nation states will be absorbed. A "third world war" is not avoided by the self determination of the nation states, but it is not to be blamed on their self determination either. It is the mechanism through which the NWO will emerge.