I agree with you that those relationships are tenuous at best, but would invite you to re-examine your theory of "bigger messes".

In Kosovo, US-led NATO involvement may not initially have created a bigger mess than was there before, but it did involve the subsequent purging from most of Kosovo of all ethnic Serbs. And, having no central authority to speak of and essentially being run by organized crime, Kosovo is essentially now the entrepot through which heroin, sex slaves and illegal immigrants from SW Asia and SE Balkans transit. Not an ideal situation.

As for Serbia, the fact of the matter is that the NATO intervention did not drive Milosovic from power. Rather, violent Serbian protests in response to widespread election irregularities over a year later did. This election result arguably would have happened either way, given the state of the Serb economy and its painful (by contemporary European standards of the time) diplomatic isolation. The 96/97 environment was almost assuredly a thing of the past by 1999, given the deteriorating situation in Serbia even prior to the bombing campaign. In any event, arguing that intervention put Serbia on a path to western Democracy is discutable, given it has arguably not improved much since.

Also of note is the banditism in Serbia which, although not as acute in Albanian Kosovo, is still pretty bad (as evidenced by, among other things, the assassination of Zoran Đinđić by Serbian organized crime).

I'm not so sure you can say that the intervention made the situation better. In fact, I think it can be argued that it made things worse.

Unless, of course, if you are an Albanian Kosovar, and in particular if you are engaged in organized crime there.

The Hun is always either at your throat or at your feet. Winston Churchill