Re: You want to play hardball?
"a small but violent, centralised, and heavily militarily-backed-by-Russia subset of the people in Donetsk en Luhansk"
Are you quoting from a reliable source or just pulling stuff out of your arse?
My guess though, would be that they didn't want to be part of this anymore.
https://youtu.be/5SBo0akeDMY
Source: BBC