The idea of a world government IS the No. 1 threat to humanity as of today.
Millions would die right off the bat as the underdeveloped countries try to brush past developed ones — by friction in the form of riots and wars.
We're watching a Disguised Socialistic/Communist Age take shape on a World Wide Scale.... Control of resources, Communication Networks, Medical Availability, Economies, Technology, etc.etc.
It will happen in time and tide. As Christians we should expect this just as is written it will.... But we're going home!