Sloboda Ukraine

I will begin with the most outlying region of them all, so called Sloboda Ukraine or Slobozhanshina. Back in the days it consisted of Kharkiv oblast as well as half of Sumy Oblast. 

This area was first to use term Ukraine for itself. Sloboda part of name means 'free' and together give Free Ukraine.

However, this name is a misnomer created for propaganda purposes, it was never a part of Hetmanate and was always ruled directly by Moscow.

The term free used to mean free of taxation. Back in the days Moscow exempted this area from taxation to encourage settlement.

Even though this area also calls itself Ukraine, its idea of what Ukraine is, is vastly different from that of the rest of the country. 

It is a completely different from Ukraine proper area, that also happen to use term Ukraine to refer ot itself. 

Compared to the rest of the South-East, Sloboda Ukraine was settled about 200 years earlier. Because of that this area can be considered South-East's older brother. However, it was settled under Moscow rule just as other parts of South-East.

Sloboda Ukraine Republic

This is first of my new proposed nations that will take areas from both Russia and Ukraine and unite them into a meaningful new nation state.

Because city of Kharkiv itself is very close to Russian borders, it is geographically and economically anchored to that area.

On Russian side of the Border city of Belgorod is equally close to the border.

The twin cities prevent Russia and Ukraine from going their own way.

Because of that it would be natural to take these two oblasts and make a new nation out of them. I think they will make a good nation together. 

Northern parts of Luhansk Oblast that are mostly agricultural unlike the mostly mining towns south will make a nice addition to this new nation.

Russian Kursk Oblast can also be added to this new nation.

City of Sumy can also be added to that nation, but I think they are better off in the Ukraine proper.

Both Belgorod and Kursk located in Russia's dark corner and are often overlooked by Moscow. So being part of small nations will allow these areas to be heard and cared for much better than being part of big Russia.

Politically it can be a win for both sides. The area in question has little strategic value for Russia, but creating this state can help Russia recover some of its lost reputation and lift some of the sanctions imposed by the West.

Ukraine on the other hand will get a buffer state on its border with Russia and expense of a problematic region.

Since new nation will consist of areas of both Russia and Ukraine, it will not look like loss for either side.

World too will benefit from a neutral buffer state that will divide warring states and prevent further wars.