NATO fought for all the peoples of Yugoslavia to have self-determination, and against the chaos of Serbs who wanted to deny self-determination to Muslim Bosniaks and Albanians/Kosovars. Preventing a fascist regime from strengthening itself on one's borders is self-defense for Europe. I say this as an Orthodox Christian myself who loves the Serbian liturgy, but some of them were being very wrong and evil to do what they were doing in the 1990s.