Defence secretary visits Norway as Nato conducts exercises with 30,000 troops

While the war has escalated, Nato has trodden a path between supplying military hardware to Ukraine while avoiding being drawn into military action itself.

But in the last month, 30,000 Nato troops have been training in a fictitious scenario in which Norway is being invaded by an unnamed nation.

Beyond immediate threats, the arctic region could become a battle front in future as climate change opens up previously ice-covered territory and resources.