Imagine for a moment this being an unending war. Russia knocks down buildings that simply prevents the Ukrainian people to return to a major section of their country. Western Ukraine, if Russia can be contained in the east may very well be able to sustain populations again, however, what if after some reconstruction and return Russia once again decides to kill and destroy?
The two countries need a demilitarized zone with a clear understanding that if either of them cross that region of land it will be considered an assault on international stability and the ability of feed the world.
Regardless of North Korea's insistence on reunification of the people removing any agreement to peace, South Korea has been able to build a country that is successful with full engagement of the international community. South Korea is considered a great country.
There is no reason why Ukraine cannot succeed in the same way. If Russia insists on war and does not create a demilitarized zone, then the United Nations Security Council and the General Assembly must begin to build it's strongest sanctions and isolation of Russia. What also needs to occur are global plans to instill a demilitarized zone and movement toward that goal. That global agreement must at least try to include China.
