Sadly since recorded time the masses have proven they seek to be ruled over and will mob up against those who don't bend knee to their rulers.
World citizenship is already here, they just obscure much of it through corporations and feel good platitudes that appeal to those who prefer being taken care of over freedom.
It's amazing really how small a percentage of folks needed to fight off England at the inception of the nation.
Most folks either rooted for England or didn't care as long as they were left alone (as long as they paid their tithing taxes).