Russia wants to retain influence and de facto unity. Basically maintain status quo.
China is threading belt road via Belarus. Massive economic interests and consequences for failure to achieve this.
US wants to reduce influence of both of the above and pull Belarus into its own sphere of influence.
No, I think your definition of politics is too restricted. There's no need to support opposition of any politician to be political. If it were, anarchists wouldn't be classified as political, which is absurd.
That's my whole point, it's simply an uninteresting discussion about which definition of politics is "best".