Exterminating languages is one way to put it, progress is another.

Languages have died throughout time, as long as the language is preserved in a book for scholarly reasons I see no issues.

It also depends on how it's done, politically or through violence.

Oh come on!

Every state has a long history of opressing others, I'm sure Russia did it too, but to be honest being from western Europe I have my own colonial history to come to terms with before looking at others'. What I know about XXth century Russia, though, is that at some point and in some places at least they went as far as inventing writing systems for local languages that had none so that teaching could be done in that language; so that exemple alone is enough to tell me that your viewpoint lacks nuance, to put it very mildly.

History of civilizations is certainly interresting but this is not even the point; the point was: why should the interrest of a text from Nabokov about the Russian language be seen through the lense of some modern episode of political violence? This is obvious nonsense, yet it appears to come up frequently, sometimes, with some people. Why? And what can be done to stop the contagion before mankind revert back to clan warfare? (because if we want to look for reasons to hate each others in past or modern politics, sure enough we will get there!)

This is false.

Colonization of eastern parts of russia involved forced conversion to christianity, violence, rape, mass murder, but not language extermination

Even culture extermination is an exaggeration, sure some areas got forcibly "converted" to christianity (if they were unlucky to be invaded before USSR) but you will see mosques/buddha statues/whatever is applicable and all the local traditions and beliefs mostly going like before

Actually in areas where local languages exist they kept schools teaching local languages and official signs are duplicated in both local and Russian all the way from USSR. I know this first hand;) but even the article you linked will tell you that.

So it was maybe not as good as support for indigenous languages in Canada but not extermination

Only since 2018 it is optional to teach local language in schools, previously there were at least some schools that teach it in every area like that. thank Putler for that too.