As someone said , Ukraine is different to Syria . Russia has long history with Ukraine . And this military campaign , has been remarkably free of casualties , considering the amount of ground covered . Yes 100 casualties is high per day . But very low , if war lasted two days , for a country size of Europe ! Therefore chances of reconciliation are high , once the extremists are removed from power , and elections held . Then Russia need not hand out 250 billion , to support economy . It can simply carry out similar reforms , as it did for itself , to rescue economy , post Soviet collapse . Putin has good knowledge of those reforms , that rescued Russia .
Therefore keeping a unitary state is possible . Should form the core plan . However if civil war is endemic and the resources to keep this together , is too high , then allowing for partition , may be unavoidable for Russia . But then the western part may host NATO . In that case Russia can host Nukes in the East . But that is further down the line .