The terms under which those countries were allowed into the EU were largely about building strong anti-corruption measures and improving transparency in government.
Supernational institutions like the EU and UN can do great things like this.
Starting with "For examples of this".
>>Supernational institutions like the EU and UN can do great things like this.
Well, give me some examples where corruption of a political system was solved by external organisations?
(And NOT in a military way.)
(The main benefit East Europe got was a pressure to conform with EU criteria to get into the trade union. That solved quite a lot, by paying the political leadership to solve their problems... This can only be done once. But Romania and Bulgaria got into EU without fulfilling those criteria, probably by bribing for the EU votes (as I understand it, a few large companies were sold cheap to French, Belgian etc companies). So corruption worked for them... not even here, with a big carrot, was it solved by the EU!)
Edit: I might add that the UN is infamously corrupt and many functions are taken over by dictators, working for their combined interests. (If you're Swedish, you won't read about that in your local media.) Hardly able to help anyone with corruption...
My original point was that to make a country a nice place today is not rocket science, the failures either seems to be an ongoing conflict -- or corruption.
Afaik the methods to stop corruption isn't that hard to design, the hard part is to get a political class to implement them. To do it from outside is impossible without an invasion, you have to get the population to pressure the criminal thieves (a.k.a. politicians).
(I guess 'fulafel' is a naive Swede who grew up believing his own media, like I did. That is why I bother with this.)
Disclaimer: No political science education, just a hobby to read to try to understand the world,