The Russian navy — already badly depleted since the collapse of the Soviet Union — can’t quickly replace most of its existing nuclear submarine fleet, which is approaching the end of its collective lifespan. The outcome will likely mean a shrinking of the Russian nuclear submarine force in the years ahead.
This is a serious problem for Russia whose naval needs center around nuclear submarines. Russia needs ballistic missile nuclear submarines (SSBNs) for a survivable nuclear deterrent and nuclear attack submarines (SSNs) to protect the SSBNs in bastions close to Russia.
Cruise missile subs are a luxury Russia can ill afford with the shrinkage in their SSNs and SSBNs.
And large surface ships are pointless.
Add to a core of nuclear-powered subs a force of small surface combatants as a coastal defense force and the Russian navy is complete as far as Russia's defense needs go, which must emphasize ground forces and air power to support ground troops for the defense of Russia's long border.
Yet the Russians can't manage to maintain the strength of their key naval force.