The arrest of war criminal Ratko Mladic, alleged architect of the Srebrenica massacre in 1995, tears down one of the remaining barriers preventing Serbia joining the European Union.

BELGRADE, SERBIA - FEBRUARY 24: A Serbian Radical party supporter holds a photo of war crimes suspect Ratko Mladic at a rally in Belgrade February 24, 2006. A Serbian ultranationalist party on Thursday urged fugitive Bosnian Serb general Ratko Mladic not to surrender to the UN warcrimes court, despite mounting pressure on Belgrade to hand over one of the most wanted suspects of the Balkan wars in 1990s. (Photo by Milos Bicanski/Getty Images)

69-year old Mladic was a leader of Bosnian-Serb forces during the Balkan wars during the 1990s, and is wanted for war crimes, including genocide, dating from that period. The July 1995 assault on Srebrenica led to the deaths of 8,000 Muslim men and boys in one of the worst acts of "ethnic cleansing" since the end of the Second World War.