There are about 25 million persons of Russian ethnicity living in what was the Soviet Union outside of the Russian Federation.
The Russian Federation will protect these people as it deems necessary.
The Russian Federation will not tolerate systemic discrimination against them by Ukraine or other post-Soviet government.
The Russian Federation can not support 25 million Russian refugees.
In 1957, Eisenhower sent federal troops to Little Rock, Arksnsas to end discrimination.
The Russian Federation will give citizenship to any former Soviet citizen and their descendents if they want it. Also they can serve in the Russian Armed forces. Thus why you see Kazakhs, Uzbeks, Belarusians, ect in the Russian Army. They can also serve in Wagner group if they did a tour with their local Armed forces (CSTO only).