That was a test case for converting NATO into an offensive organization. I doubt that many of us realized what was going on there.
Oh, NATO had already been offensive* in Bosnia-Hercegovina and Croatia before the 1999 bombing of Serbia, but yes, that was the first “big one”.
Funny how R2P was championed and deemed morally justified when NATO took the side of Islamic terrorists (KLA in Kosovo, LIFG in Libya) but it’s “unprovoked aggression” when the Russians defend the people of the LDNR who have endured constant shelling and bombing since 2014. Also interesting that “disproportionate force” was cited as the reason for massive bombing by NATO in both cases. Hello?
*Yes, double entendre intended.