A possible reason: nobody buys it when Russia says they support democracy. Another point worth bearing in mind: three days of supporting protestors probably wi

A possible reason: nobody buys it when Russia says they support democracy. Another point worth bearing in mind: three days of supporting protestors probably will not compensate (from a "hearts-and-minds" perspective) for three decades of supporting their tyrant, quite irrespective of any realpolitikal justifications that may exist.