Start with this:
European Identity, Zlatko Tisljar Assoc. for European Consciousness Maribor 3/8'11 http://www.debatingeurope.eu/2011/08/03/should-esperanto-be-the-language-of-europe/#.V53JpLh95hF
Language is a package (communication part) of cultural (+) IDentity.
For cross-cultural communication we need a Neutral language that is not forced by commercial gains and is fair on all sides.
Soviets & Yugoslavia were unaware of role of language in identity, & they tried to develop Soviet/Yugoslav language of largest population; it did work as language of communication but could not be accepted as language of communal identity, because it wasn’t neutral. For this reason, they failed to develop (cross)communal identity. In time of crisis this was decisive & fundamentally influenced collapse of these multi-ethnic states. Without solution to this problem European Union will fall apart whenever first large scale economic or political crisis occurs...