“The movement of the S-300/400s is not merely a redeployment of forces. The multi-layered structure that Russia has built has been significantly undermined, the [Anti-Access/Area Denial] A2/AD bubble that has been responsible for strategic deterrence against NATO has shrunk, and surface-to-air air defense in the Bastion strategy has been weakened, forcing a transformation of the defense structure,” it adds.

Katarzyna Zysk, a professor with the Norwegian Institute for Defense Studies, told Radio Liberty that thinned-out defenses in the far north suggest Moscow does not anticipate imminent escalations in the region.

“It suggests that Russia does not anticipate an imminent large-scale attack in the [far north] region and judges that it can reduce protection there without incurring unacceptable risk,” Zysk said.