Most of the writers who were for it during the old days were back when Europe controlled the world so by homogenization they mean a huge european state, but that is not feasibile anymore. Eu sucks, Europe is now 8% of global population (ie back in 1900 they used to be ~30% of the global population) , globalism was ruined by civil rights , and autarky is probably the future. Also wars probably will not break out with the dispersion of nuclear arms.
Updated