Do you ever look at a geographical map? South Ossetia declared independence from Georgia in 1990, as the Republic of South Ossetia. The Georgian government responded by abolishing South Ossetia's autonomy and trying to re-establish its control over the region by force.
As for Chechenya, it is part of Russia since ... the Caucasian War; it was first incorporated as a whole into the Russian Empire in 1859.
Crimea was part of the Russian Empire since ... the Russia-Ottomans war, 1774.
This comment is besr read with the Red Army Chorus singing in the background.