Russia's military posture and the deployment of S-400s in its Western Arctic reflects the Soviet legacy of bastion defense comprised of "concentric circles" designed to protect strategic territory.
Russia's priority is to defend its northwest coast and the surrounding maritime domain housing the Northern Fleet, Russia's most capable naval force. It also aims to reduce its strategic vulnerability in its Far North. S-400s and other assets are the groundwork for an established anti-access/area denial (A2/AD) network.
GEOINT analysis confirms the deployment of the S-400 air defense system to Rogachevo Air Base on Novaya Zemlya archipelago from Russian public declarations. Press release vs. imagery validation methodology is simple yet effective when tracking progress or lack thereof.