Croatia, the most advanced of the former Yugoslav candidates, is being blocked by its neighbour Slovenia, which joined the EU in 2004, over a boundary dispute.
The European Commission this week reported on two official candidates, Croatia and Macedonia, and assessed progress in Albania, Bosnia, Montenegro and Serbia.
Serbia and Bosnian Serbs responded with armed attacks on BH Croats and Bosniaks aimed at partitioning the republic along ethnic lines and joining Serb-held areas.