When Russia invaded Georgia Bush sent warships into the Baltic and launched a resupply airlift. Had Putin responded militarily he could have set off a war with NATO that could have escalated into a nuclear exchange. Since that time the Russian strategy to retake the wayward republics has been limited to economic and political subversion. But if these protests spiral Putin may feel the only alternative is force.
No one to stop him now unless they are muslims and need support or protection.