There is a new wave of Kremlin criticism in Russia and this time is more interesting as it is not supported or galvanized by the West.
The wave of criticism has been sparked by Navalny (a nationalist, anti Muslim politician, now under arrest) against the high level of corruption and poor economic situation of the average Russian and the constant war spend
This always have been the biggest issue for Putin – while he is probably one of the greatest foreign policy experts, the focus in the internal economics of Russia has always been lucky (even if to reform the highly corrupted Russian economy would be a hard feat also for him).
Probably Putin’s greatest error has been not to take advantage (for the whole economy, not just for himself and friends) of the commodities boom to restructure the economy.
These criticisms will not be unmanageable for Putin and the security apparatus, but will provoke a shift not so dissimilar to Tiennamen Square for China.
Also, in Russia is always better to consider what you wish for.
Amongst the Russian leaders, from an historical perspective at least, Putin has been quite a pacific and non-violent leader. Russia is a harsh land that breeds arsh leaders.