Russia Ukraine war, page-73542

wont give up ethnic Russian territories

The Russification of the area,(Donbas), accelerated after the 1958–59 Soviet educational reforms, which led to the near elimination of all Ukrainian-language schooling in the Donbas. According to the Soviet Census of 1989, 45 percent of the population of the region reported their ethnicity as Russian.

https://greekreporter.com/2022/09/30/history-donbas-donetsk-luhansk/#:~:text=The%20Russification%20of%20the%20area,reported%20their%20ethnicity%20as%20Russian.

so still majority ethnic Ukrainian , not that ethnicity is a definitive arguement for secession and their are plenty of ethnic russians fighting for Ukraine .
Nor was there any secession as russia is seeking to "annex" ... ws always just a a land grab for the empire !