Operation Deliberate Force was a sustained air campaign conducted by the North Atlantic Treaty Organisation (NATO), in concert with the United Nations Protection Force (UNPROFOR) ground operations, to undermine the military capability of the Army of Republika Srpska (VRS), which had threatened and attacked UN-designated "safe areas" in Bosnia and Herzegovina during the Bosnian War with the Srebrenica genocide and Markale massacres, precipitating the intervention. The shelling of the Sarajevo marketplace on 28 August 1995 by the VRS is considered to be the immediate instigating factor behind NATO's decision to launch the operation.The operation was carried out between 30 August and 20 September 1995, involving 400 aircraft and 5,000 personnel from 15 nations. Commanded by Admiral Leighton W. Smith Jr., the campaign struck 338 Bosnian Serb targets, many of which were destroyed. Overall, 1,026 bombs were dropped during the operation, 708 of which were precision-guided. On 19 occasions, depleted uranium munitions were used against targets around Sarajevo and Han Pijesak.The bombing campaign was also roughly conterminous in time with Operation Mistral 2, two linked military offensives of the Croatian Army (HV), the Army of the Republic of Bosnia and Herzegovina (ARBiH), and the Croatian Defence Council (HVO) launched in western Bosnia.

The Bosnian War (Serbo-Croatian: Rat u Bosni i Hercegovini / Рат у Босни и Херцеговини) was an international armed conflict that took place in Bosnia and Herzegovina between 1992 and 1995. The war is commonly seen as having started on 6 April 1992, following a number of earlier violent incidents. The war ended on 14 December 1995. The main belligerents were the forces of the Republic of Bosnia and Herzegovina and those of Herzeg-Bosnia and Republika Srpska, proto-states led and supplied by Croatia and Serbia, respectively.The war was part of the breakup of Yugoslavia. Following the Slovenian and Croatian secessions from the Socialist Federal Republic of Yugoslavia in 1991, the multi-ethnic Socialist Republic of Bosnia and Herzegovina – which was inhabited by mainly Muslim Bosniaks (44%), mainly Orthodox Serbs (32.5%) and mainly Catholic Croats (17%) – passed a referendum for independence on 29 February 1992. Political representatives of the Bosnian Serbs boycotted the referendum, and rejected its outcome. Anticipating the outcome of the referendum boycotted by the majority of Bosnian Serbs, the Assembly of the Serb People in Bosnia and Herzegovina adopted the Constitution of the Serbian Republic of Bosnia and Herzegovina on 28 February 1992. Following Bosnia and Herzegovina's declaration of independence (which gained international recognition) and following the withdrawal of Alija Izetbegović from the previously signed Cutileiro Plan (which proposed a division of Bosnia into ethnic cantons), the Bosnian Serbs, led by Radovan Karadžić and supported by the Serbian government of Slobodan Milošević and the Yugoslav People's Army (JNA), mobilised their forces inside Bosnia and Herzegovina in order to secure ethnic Serb territory, then war soon spread across the country, accompanied by ethnic cleansing.

The conflict was initially between Yugoslav Army units in Bosnia which later transformed into the Army of Republika Srpska (VRS) on the one side, and the Army of the Republic of Bosnia and Herzegovina (ARBiH), largely composed of Bosniaks, and the Croat forces in the Croatian Defence Council (HVO) on the other side. Tensions between Croats and Bosniaks increased throughout late 1992, resulting in the escalation of the Croat–Bosniak War in early 1993. The Bosnian War was characterised by bitter fighting, indiscriminate shelling of cities and towns, ethnic cleansing, and systematic mass rape, mainly perpetrated by Serb, and to a lesser extent, Croat and Bosniak forces. Events such as the Siege of Sarajevo and the Srebrenica massacre later became iconic of the conflict.

The Serbs, although initially militarily superior due to the weapons and resources provided by the JNA, eventually lost momentum as the Bosniaks and Croats allied against the Republika Srpska in 1994 with the creation of the Federation of Bosnia and Herzegovina following the Washington agreement. Pakistan ignored the UN's ban on supply of arms, and airlifted anti tank missiles to the Bosnian Muslims, while after the Srebrenica and Markale massacres, NATO intervened in 1995 with Operation Deliberate Force targeting the positions of the Army of the Republika Srpska, which proved key in ending the war. The war ended after the signing of the General Framework Agreement for Peace in Bosnia and Herzegovina in Paris on 14 December 1995. Peace negotiations were held in Dayton, Ohio, and were finalised on 21 November 1995.By early 2008, the International Criminal Tribunal for the former Yugoslavia convicted forty-five Serbs, twelve Croats, and four Bosniaks of war crimes in connection with the war in Bosnia. Estimates suggest around 100,000 people were killed during the war. Over 2.2 million people were displaced, making it the most devastating conflict in Europe since the end of World War II. In addition, an estimated 12,000–50,000 women were raped, mainly carried out by Serb forces, with most of the victims being Bosniak women.