"That wasn't 'aggression' - that was a UN-sanctioned response to Serbian genocide (the UN's term, not mine) in the former Yugoslavia. You can no more describe this as NATO aggression than you can describe the allies going to war against the Nazis as 'aggression' against Germany!"
it's because Russia was weak at the moment, it had nothing to do with "genocide" or other made up bs, there are hundreds of thousands Albanians living in other parts of Serbia, if you really believe Serbs were inclined to do those things to Albanians but only on Kosovo then you really are brainwashed
If it happened some 5-10 years later Putin would step in and protect Serbia the same way he protected Syria(actually Assad) from announced american&NATO bombing campaign.
It's called geopolitics and very rarely has anything to do with minor nations like Serbs&Albanians(although these would argue about their "significance").