Operation Deliberate Force was a sustained air campaign conducted by NATO, in concert with the 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.