Power struggles inside the Kremlin
Probably better here than good reads, though it is a good read, I think.
https://www.opendemocracy.net/od-russia/vladimir-pribylovsky/power-struggles-inside-kremlin
Moreover, not one of the oligarch clans, nor any of the influential courtiers in the Kremlin, call for returning Crimea to Ukraine, regardless of the possible concessions (from cancelling sanctions to guarantees of non-NATO membership or EU accession).
Members of the economic-administrative clans (who come overwhelmingly from civilian sectors), are supporters of a safer policy of rapprochement with the West. But others with backgrounds in the security services prefer confrontation with the West and co-operation with Asian elites. The most pro-China politician in Putins circle is most likely Igor Sechin.
At the most basic level, the Orthodox Chekists are former members of the KGB and FSB who identify not so much with Felix Dzerzhinskys ruthless Cheka (from which Chekist) and the communism of Lenin and Stalin, so much as Russian nationalist groups, existing and otherwise. This group is centred around several nationalist organisations, such as the St Andrew the Apostle Foundation. While the chairman of the organisation, Vladimir Yakunin, is the head of Russian Railways, the president is the railroad banker Mikhail Baidakov. The Minister of Culture, Vladimir Medinsky, is close to Yakunin and his foundation. Medinskys father-in-law, Oleg Nikitin, is the head of the Federal Passenger Company, which, likewise, is affiliated with Russian Railways.
Sounds a bit like the US in the 1890's.