One world governments in science fiction ?

Hi All, 

Science fiction has often trailed science fact , whether we like it or not, but one thing that has not yet materialised is one world government. Yes I know that space travel and warp drives aren't around either, but the first is actually possible (no the earth is not a disc, but a sphere) and the second is in theory possible, it's on the to do list if humanity can survive humanity...

But one world government, to my mind, seems more outlandish than either a warp drive being invented in someone's shed . Or  for that matter aliens landing in Jerusalem to have a cup of tea with the Chief Rabbis .(Okay I shall be ecumenical) . A one world government seems to me to be more outlandish than aliens landing in Jerusalem to have a cup of tea with the Chief Rabbis, then heading off to Constantinople  for lunch with the Orthodox Patriarch, going over to the Vatican to see the Pope for afternoon tea and finally landing in Canterbury to have supper with the Archbishop and then going to Mecca for a swift half before closing time, before an all night pissup with Buddhist monks and Hindu Vedics. 

However , for the purposes of this blog post I shall muse as to what a world government would look like and it is easy. The UN would not be the role model, in fact if you ever wanted to get a whiff of what a one world government would look like it is the EU, in fact replace European with Earth and you already have an excellent name for a human government. A world government would not be either a military or imperial dictatorship or a liberal democracy on American, Westminster or the European systems. It would be like the EU- a government in effect led by bureaucrats- but like Imperial Germany in the nineteenth century,  it would have a 'fig leave of democracy' with a Parliament that had minimal powers. It would have 'state' governments, 'frugal fours' etc,  wealing and dealing in late night summits, looking after their corner. But after any agreement was signed the implementation, interpretation and supervision would all be in the hands of the bureaucrats and not elected officials.  Big mega corporations would love this set up, but small businesses and venture capitalists would loath the red tape and form filling required to get anything done. I would suspect that there would be a bare bones military more of a heavily armed Federal police force and if mankind had colonised star systems then it would be the larger mega corporations that would do the colonising and therefore  have private forces of their own, in a same way the various European 'east India' companies fielded their own warships and armies. 

Having written this , I don't think it is possible. There are many reasons for this and you could write a book on it. But I suspect that even if aliens did come to Earth, each nation would be vying for whatever they could get or trade, rather than this creating a new world government. After the initial shock, aliens would be old news on social media.