The Arctic, once a region of peaceful cooperation, is fast becoming a battleground for resources and territory.

At the heart of it is Norway – bordering Russia and hosting the secret military headquarters inside a mountain where any potential war against Russia would be co-ordinated with Nato allies.

Watch the BBC’s Europe editor Katya Adler go inside that command centre, and on board Norwegian warships leading military exercises in Arctic waters.

Tomorrow, you can read her analysis on why Nato is having to rethink its tactics in the High North.