Saying that Serbia was establishing order within its territory is a bit cynical take. What they did is that they systematically[1] cleansed villages and settlements in order to decrease the percentage of Albanian population in Kosovo.

In a way, they were implementing a century old policy of a guy named Vaso Cubrilovic who argued that Albanians should be expelled[2] from the lands Serbia (precursor of Yugoslavia) took in 1913.

What NATO did, is stopping exactly this from happening.

[1] https://www.hrw.org/report/2001/10/26/under-orders/war-crime...

[2] https://en.m.wikipedia.org/wiki/The_Expulsion_of_the_Albania...