Nationalism is in direct conflict with a world government. Even if we take the lightweight version of this in the form of the U.N. - nations do not universally

Nationalism is in direct conflict with a world government. Even if we take the lightweight version of this in the form of the U.N. - nations do not universally accept the Universal Declaration of Human Rights. Wealthy+industrialized+militarized countries who are U.N. charter and Geneva Convention signatories, violate those agreements when it suits them. The conditions by which nations voluntarily joined the League of Nations (what eventually became the U.N.), and were willing to ceded national sovereignty, was WWI and WWII. All deaths are measured in the millions: just the Axis military deaths was multiple millions, total causalities upwards of 80 million. A world government will take two things, in my opinion: an event that demonstrates such betrayal by national governments, that makes them partly or entirely illegitimate by their very nature; the ensuing catastrophe is not so bad that organizing a world government is rendered impossible.