The current situation can be sustainable, but so far it is very delicate to speak about the ending of the civil war in Ukraine. A few more steps are needed both from the Ukrainian leadership but also from Europe to end the civil war. In my view, the key priority is decentralisation in Ukraine; the initial, at list declaratory steps, have been done. But this process is not completed, and more needs to be done to be able to speak with more certainty about the ending of civil war in Ukraine.
As far as I see the sanctions process in different parts of the world, it is sometimes easy to jump in with starting sanctions, but always difficult for bureaucratic and political reasons to stop the sanctions and come back to the normal situation. In fact, sanctions as I and many other European analysts see it, damage Europe no less and maybe even more than Russia, and do not help to solve any problems. They just distance Europe and Russia even more.
If I were deciding on the sanctions in Brussels, I would immediately stop the sanctions process against Russia. I would do this not just in the interest of good progress in Eastern Ukraine and stopping the military phase of the conflict, but I would stop them because for the EU it was a wrong step. But I am not in Brussels, so my estimate is that it will be quite a long process that Russia will not be in a position to influence because it is up to the EU to do their own thinking, re-thinking, and homework.