This is really an interesting question. The French, however, decide it simply: Nicolas de Stael = French painter of Russian origin - though he has lived in France for 15 years, no more, and was naturalized after the war (in 1939 for lack of citizenship, he volunteered in the Foreign Legion) and he himself, when he was somebody wrote in a letter that he is de great French artist, responded, "Well, the French, it will be clear after my death ..." even fantazmiroval about to leave with his family in the USSR.
Jules Paskin (people with the truth is difficult to determine the nationality) is also considered a French artist, although I'm not even sure that he had French nationality, etc., that is, as soon as some people creative profession reaches a certain stage of fame, it is introduced in terms of national geniuses - a human being is understandable
But the curious thing: in the references to the musicians can read that Sviatoslav Richter and David Oistrakh is now the number of Ukrainian pianist and violinist, in a time when the same references, Vladimir Horowitz and Jascha Heifetz are defined as an American pianist and violinist of Ukrainian origin, and my beloved friend of the pianist and composer Alika Rabinovich, accidentally born in Baku, generally called the Azerbaijani composer.
Probably, people always tend to be proud of coming from his country, attained fame abroad, in general, to be ashamed of this, in my opinion, it is not necessary, but should try to find out how people defined themselves, how deeply he felt their relationship with their historical motherland (you can to say that she had become a rather strong). I can say from personal experience: people who moved to live in another country, it is difficult to define itself: with the French we say "they are Russian, with Russian -" they, the French ... Thus here
Yes, and more: it also happens that in the transition into the category of "artists of Russian origin, the price of the order of increase. Of course, I do not mean Rothko or de Stael, but look, there is, for example, that the artist Mel Mutter, a Polish Jew who lived in Paris, her paintings have long been exhibited frequently traded with relatively stable prices, and a few days ago I saw a a directory that it is finally listed as didst join the order of Russian artists (I have long waited for this moment, one of my friends have her picture, which he would like to sell). If promotion is skillful, then I bet that within a few years it will significantly improve Quotation