The problem with diplomacy now is that Ukraine and Russia are sworn to disagree at all levels and on all points. These are even distinctive in the ways their respective leaders spar off with each other in less staged environs.
The belief of most of the Russian leadership is that their President is a firm and stoical guardian of their peace and security, and any agreement has to fall in line with this almost sacred duty.
The limitation in Ukraine by comparison is that such a bombastic military establishment doesn’t concede so easily, and its public representatives struggle to accept any moves toward peace.
This may be appear to be a contradictory state of affairs, but clever minded students of both have found equally respectable ways to the top, and there is a semblance of balance between them that makes up a peaceful coalition.
It’s the perspective used to define a settlement that allows two sides to coexist apart from a mutually assured destruction in the short term or over many conflicts. However, this is a theory of the outside and it doesn’t always seem so.