From the russian view they are fighting an exiatential threat here though. They need to get off the plain to a shrunken border they can defend and that means being in poland and also going a bit further south to natural chokepoints. The alternative is joining the wwstern party and that means elections and reforms that would inevitably remove most of the current elite from power and decimate their earnings. Further their demographics are waning to the point they wont be able to field much of an army in the coming decades vs now so that outs more pressure on them to respond now. To me its strange to think it will stop here now that russia has paid such a high price. Its do or die time for their elites.