Origin of the conflict
Bosnia-Herzegovina formed a part of the former Yugoslavia between 1942 and 1992, together with Slovenia, Macedonia, Serbia, Kosovo, Montenegro and Croatia. Separatist sentiments increased after the death of President Tito, leading to independence of Slovenia and Croatia in 1991. Bosnia declared itself independent from Yugoslavia (Serbia) in March 1992 after a referendum that was boycotted by Bosnian Serbs.

Chronological timeframe
In May 1992 the Bosnian Serbs had occupied 70 percent of the country. Serb leaders aimed at creating a larger Serbia, which would incorporate Serbian areas in northern and eastern Bosnia, including the city of Sarajevo. The Serb leader Karadzic and General Mladic, supported by Yugoslavia (Serbia), started to expel Muslim and Croat minorities from what they considered Serb land. War raged over the country between 1992 and 1995. As a result, 200.000 people died and 1.8 million (almost half of the total population) fled.  The Bosnian Croats started in 1993 a campaign to establish a Croat territory in areas bordering Croatia. In March 1994, the Washington Peace agreement established a ceasefire between the Bosnian Croats and Muslims. This did not end the war with the Serbs, which ended with the Dayton Peace Agreement in 1995, mediated by the US. It divided Bosnia-Herzegovina in the Republica Srpska and the Croat-Bosniak Federation. Various international organizations were involved in the peace building afterwards. A European Union Police Mission (EUPM) and peacekeeping forces of the EU (EUFOR) were in 2009 still necessary to provide stability.

Response of the international community
The UN-protection force UNPROFOR, already present in Croatia, was expanded to Bosnia in 1992, but UNPROFOR was neither mandated nor equipped to impose peace and engage in fighting enemy forces. This mandate seriously hindered the UN’s effectiveness. The led to the conquest by Serb forces of the ‘safe area’ of Srebrenica in eastern Bosnia, when UN blue helmet soldiers from The Netherlands were unable to prevent 7.500 Bosnian men inside and outside the enclave from being killed. In June 1995, another massacre threatened Gorazde and NATO members issued a deterrent warning that Serb targets would be attacked by air. When Serb attacks continued on Sarajevo, the British, French and Dutch military responded with air strikes and artillery against Serb military targets. Meanwhile, the Croatian army had attacked Serb areas in the Krajina in August and expelled the population to Serbia. 

International Criminal Tribunal for the Former Yugoslavia
The International Criminal Tribunal for the Former Yugoslavia (ICTY) in The Hague issued indictments against 161 individuals accused of committing war crimes. In mid 2009, 60 war criminals had received sentences for serious violations of international humanitarian law, including the major suspect Karadzic, but not yet Mladic. In 2007, the International Court of Justice ruled that Serbia had been negligent in preventing genocide in Srebrenica. 
 

Sources
International Criminal Tribunal for the Former Yugoslavia (ICTY), www.icty.org. 
Joris Voorhoeve (2007) From War to the Rule of Law, Amsterdam: Amsterdam University Press.
Netherlands Institute for War Documentation (NIOD)(2002) Srebrenica, a 'safe' area. Reconstruction, background, consequences and analyses of the fall of a safe area, J.C.H. Blom, Peter Romijn e.a. Amsterdam: Boom. http://srebrenica.brightside.nl/srebrenica/.