In 1999, the armed confrontation between the Kosovo Liberation Army (KLA), an ethnic-Albanian militia, which had supported Kosovo's independence since the 1990s, and the Serbian army and police led to NATO airstrikes against what was former Yugoslavia.
The military operation was conducted without the approval of the UN Security Council and on the basis of the Western countries' allegations that the Yugoslavian government had carried out ethnic cleansing in Kosovo against Albanians. It remains a controversial subject between Albanians, who see NATO's interference as a protective measure, and Serbs, who condemn the operation for killing civilians in the airstrikes.
