In Germany, there was a big celebration. Many people would say that they are happier now then before. Others would say that the old country was better, because for many of them it was the only one they had since they were born there. A few would say that they hate everything, old countries, new countries and other people. Jewish synagogues were burning in the night before the big celebration and on the museum, the former concentration camp Buchenwald swastikas were painted again.
Hate is a long lasting poison.
You would get the same result if you asked people of former Yugoslavia. Many in those newborn little countries will be glad, many will feel sorry about the former state and quite a few will say that they hate everything and everyone. Since the division is done and there is no external war, they will go on fighting each other, be it for the so-called power, be it for the pleasure and excitement of the adventure, but most of all for hate and bitterness. History tends to reprisals. Maybe Yugoslavia will be united again one day and maybe one day the USA, Canada, Spain, the United Kingdom or some other country will disintegrate.