The need to learn Russian has arisen a long time ago, in the epoch of the formation of the Russian state, and then the USSR, where the Russian language continued to be the language of inter-ethnic communication.
Russian as a foreign language was mainly taught in foreign countries, including in the Warsaw Pact countries.
In the CIS and Baltic countries, due to the preservation of a fairly significant Russian-speaking space, it would be more correct to speak of teaching Russian as a second language, since in most cases English is studied as a foreign language there.
Currently, the demand for quality education in Russian, including improving Russian language skills, has increased significantly compared with the beginning of the 1990s, when there was a sharp decline in interest in the Russian language.
The highest demand for studying Russian language is where the proportion of Russians is small.