Since the Yugoslav wars are generally understood to have begun after Slovenia's declaration of independence in 1991, I'm not sure whether this breaks the 20-year rule on this sub. Nonetheless, the massacre at Srebrenica in July 1995 demonstrated the general impotence of UNPROFOR (United Nations Protection Force) to stop violence perpetrated by the JNA (Yugoslav National Army) in the former Yugoslavia. As a result, the international community invested currency in the North Atlantic Council and NATO. IFOR (Implementation Force), which consisted of some 60,000 troops from various countries, took over from UNPROFOR in December 1995. Its mandate provided the use of force to ensure physical security over a strict one year period. In 1996, IFOR was displaced by SFOR (Stabilization Force), which sought to maintain order and security in BiH until 2004. While the massacre at Srebrenica might have "ended" in July 1995, its consequences continued to materialize throughout the late 1990s in BiH and in Croatia. The murder of Bosniaks at Srebrenica fomented pre-existing distrust and hatred towards the perpetrators, which was employed to garner support for specific causes. For many witnesses or individuals who lost family, the events at Srebrenica didn't mark any type of end. The residual effects of the war, such as the flow of refugees/internally displaces persons, PTSD, etc., continued well after July 1995. The international community hoped to stem violence because the aforementioned residual effects of war threatened the stability of the European Economic Community and the development of the nascent European Union. The 1999 campaigns and Kosovo conflicts are beyond the scope of the sub's rules. I hope this clarifies.

I'm terribly sorry, but questions are restricted to 20 years or older. Most of the foreign involvement was during 1995 - Bosnia,and 1999 - Kosovo. As such, this isn't really within the scope of this subreddit.