There are millions of Russian ethnics that live outside the Russian Federation but in the territory that was the Soviet Union.
The cities of Moscow and St. Petersburg do not have the jobs or the housing to accommodate them.
Putin needs to be sure that Russian ethnics can remain and prosper where they now reside without discrimination.
You may think of a passport as merely an expensive ID, but it really says mess with me at your peril.
When I traverse a foreign land, my US passport implies the full military might of the USA may be applied to provide for my safety.
Lol...sure it does