The European Union resembles only partly a community in the way it works. The internal differences between the member countries, disclosed in their full strength by the financial crisis, dilute the foundations of the European unity. Will the EU survive this bend, as it has in the past, or will it share the fate of other unsuccessful political and economical unions known from history? Considering the latter possibility remains, in any case, no longer just an exercise in political fiction. The fact that the Union is not uniform has been known since it ceased to be a safe, close union of six founding countries. Yet only the extension to the East in 2004, accepting simultaneously ten new countries, gave rise to a heated discussion, whether an Union of 27 countries can work jointly at all, taking into consideration the increasingly visible disproportions between its members. It also quickly turned out that the Lisbon Treaty is just partly an answer to this dilemma. An institutional reform did not protect the Union from new, huge shocks, which the financial crisis brought with it. These phenomena create a challenge for Poland, which will take up its half-year EU presidency in the middle of 2011. They will not always agree with the plans and means concerning the realization of the planned actions.