Isolating Russia is enough. The threat is any kind of multipolarity arising. Most of Europe is in lock-step with the US on this. Anyone outside that will be targeted. The goal is a wall of Russophobia and American loyalists all the way from the borders of Russia to the Atlantic. In fact the borders of Russia are the most important part. If they can lock those down they can lock down all land-based (e.g. cheap, plentiful supply) gas transit so even if for instance uh France were to suddenly pursue a more independent foreign policy and try to buy gas from Russia and get closer, these countries between them could block that, could drive up costs, make it less economical.

The fact that the PM there has been publicly against supporting Ukraine and for reproachment with Russia is a danger and a problem. US unipolarity will not be maintained by allowing random and seemingly unimportant countries to slip through and stand up to them because enough of those form a bloc and a big enough bloc encourages those that do matter to stand up. The point of absolute power and control is keeping everyone afraid of challenging you. Of knocking out or down anyone who publicly stands against you to intimidate and keep the rest in line.

As the head wasp in A Bug's Life put it "if one ant stands up to us others might and one ant doesn't matter but if they all stand up to us we're done".

Anti-US, anti-NATO sentiment anywhere is a threat to NATO and US interests everywhere. Where one dares stand up, others might follow.

At no point has the US shown limits. At no place have they said "eh this is far enough away from our interests that we absolutely don't care what goes on here". There are only greater priority interests and lesser priority interests, a sliding scale and clearly keeping Europe in line is important and color revolutions are always a useful tool.

TBH the government probably should meet the protestors half-way. They want to reduce dependence on Chinese lithium? Fuck that. And that there could be another reason, control of global lithium supplies. Allowing an independent minded European country to build out some mining of such, one they might share with Russia is a threat.

To add to whst has been already said: a US plant might get Kosovo recognized.

vucic plays all sides so i can imagine the imperialists want a more servile goverment.

Gun markets. Those weapons flowing into Europe and through there to Africa and everywhere else? They go through former Yugoslavia. Plus it's another point of chaos, which is always a plus for the hegemon

Im not sure about the economia of Servia, but some political points:

1. Anything you gain is good
2. Weakening Russia right now is of high value
3. In the center of a lot of ex-urss
4. they have a serious communist party (not 100% sure its Servia, so maybe this one is wrong)

I think its kinda like in América Latina, the empire is taking the small countries in preparation to try to take Brasil. I wouldnt be surprised if Servia is the most politically organized (in terms of workers interest) country in the region, it makes you an important target for the empire