It seems that very few English speakers have actually mastered the Russian language as adult learners. There are many examples of English learners becoming fluent in the language, almost to the point of becoming indistinguishable from a native speaker. I know a few such people myself. However I have never met any learner who was fluent in Russian, unless they started from another Slavic language. Have you?
Let's look at some famous Russianists. Was the late Stephen Cohen actually fluent in Russian? Although the New York Times described Cohen as one of the foremost Russia experts, supposedly "fluent" in Russian, why was he still speaking through an interpreter in English on all the Russian TV interviews that I could find on YouTube? I could not find an interview with him in Russian.
I managed to find a video of the American political scientist Gilbert Doctorow speaking on a Russian TV channel, which is pretty impressive, but his grandfather is ethnically Russian, so I'm not sure if he had exposure as a kid (and the genes). But Doctorow spent more than 30 years (!!) working with Russian business and government, and even had meetings in the Kremlin.
Do you know a native English speaker who actually mastered Russian to an almost-native level (definition of C2)? How long did it take? How did you do it?
I've been learning Russian for about a year, and I've reached the B1 stage where I can have hour-long conversations in broken bits and pieces, far from fluent, but enough to keep the taxi driver entertained, for example.
What I'm wondering is, for those of you who started learning Russian to use it in a serious context: business, government, or full-time work, how many years of full-time study did it take before you considered yourself "fluent" in the language?