Violence exists not out of necessity, but basically because we like it. It is a harsh way to put it, but true. Dat power trip. Well sourced material: http://www.warandgender.com/wgmaleag.htm
Essentially, when a king wanted to conquer a province, he largely did it for the power trip feeling. Also called "glory".
A good example today is how this spirit lives on in sports, see: http://www.orwell.ru/library/articles/spirit/english/e_spirit
From a European angle, the ceding power is unlikely because nationalism. It is different from American patriotism where principles matter more than borders and the government is not conflated with society. Here, the territory, territorial integrity, and governmental structure of France matters so much in the group identity of French people that ceding power lower sounds unlikely. Ceding up (EU) is more likely because countries can still members of this higher unit as a whole. So they keep their integrity and identity. Ceding low means fracturing a country, and people will not like that, because they reify and essentialize their country/government (nationalism).
Unless a clever person can figure out a way to keep current governments as romantic emotional symbolical figureheads and cede power down in a hidden, no-fanfare way.
Violence exists not out of necessity, but basically because we like it.
This is similar to sex and reproduction. Animals reproduce not because they consciously want offspring, but because they enjoy the process itself. Likewise, violence is often enjoyed for its own sake, rather than for its material rewards. However, for humans the invention of contraceptives made it possible to decouple reproduction from sex. Similarly, once violence becomes unnecessary people will still find it enjoyable, but it may be possible to replace the actual violence with surr...
Historically, the evolution of government systems was mainly driven by violence, with invasions and revolutions being the principal agents of selection process. The rules of the game were predetermined by our environment - land was a limited resource, for which our ancestors had to compete, if only to ensure the survival of their descendants.
The 20th century introduced a game changer. As agricultural productivity in developed countries rose by orders of magnitude and natural population growth practically came to a halt, possessing a large territory stopped being a necessity. Countries with little arable land, ultra-high population density and no natural resources can now not only feed their population, but also achieve top living standards. These changes may open a fundamentally different route for societal evolution – one that would not be based on violence or compulsion.
A small thought experiment - imagine what would happen if central governments cede most powers to smaller territorial units:
Unfortunately, there are serious obstacles to the successful implementation of this idea:
Do you think these problems are solvable?