From War Is Boring: http://warisboring.com/a-grim-future...bmarine-fleet/

Introduction:

In March 2017, Russia’s new Yasen-class nuclear attack submarine Kazan launched at the northern port city of Severodvinsk. Perhaps the quietest Russian submarine ever, the event was further evidence the Kremlin can still build capable and lethal subs capable of a variety of missions, including cruise-missile attack.

But it won’t be enough. 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.