Ukraine had stable relations with Russia until they decided they wanted to align with the west and adopt democracy when there was a color revolution in 2014. If they had remained a vassal state of Russia, their relationship would still be stable.
Similarly, the situation in Kazakhstan is stable because they are a vassal state of Russia. Watch what happened when there was the beginning of a color revolution there earlier this year: Russian quickly sent troops to assist the Kazakh government in violently putting it down. If a successful color revolution was to happen in Kazakhstan (unlikely), Russia would be playing the same military games with them that they are now doing with Ukraine.
Similarly, the situation in Kazakhstan is stable because they are a vassal state of Russia. Watch what happened when there was the beginning of a color revolution there earlier this year: Russian quickly sent troops to assist the Kazakh government in violently putting it down. If a successful color revolution was to happen in Kazakhstan (unlikely), Russia would be playing the same military games with them that they are now doing with Ukraine.