Anyone in the “Near Abroad” who speaks fluent Russian and is loyal to Russia can get a Russian passport, regardless of ethnicity. In fact, anyone who had a Soviet passport could get Russian citizenship.
Ukranians can still serve in the Russian Army, per CIS regulations.
Isn’t anyone who speaks fluent English and is loyal to United States can get American citizenship and serve in US Army regardless of ethnicity?
I bet it is harder since US citizenship is a better prize but still possible for one who want it. Anyway, most of them are not bothered to learn fluent English, to be loyal to America or even to get a passport and serve to his new nation, isn’t it?
Getting Russian citizenship is a lower legue prize but still a challenge. Last time I’ve check they had world’s second largest number of illegals, right after USA.