Russia flexes muscles in challenge for Arctic control

The Russian military cargo plane flew us almost to the top of the world, to an archipelago once best known for its rare bird species and its walruses. 

Now Franz Josef Land is home to a Russian military base and the source of added tension in relations with the West.

The US has once again accused Moscow of "militarising" the Arctic and the head of Russia's Northern Fleet has told the BBC that Nato and US military activity in the region is "definitely" provocative and on a scale not seen since World War Two. 

The airfield has been upgraded to allow all kinds of planes to land all year round, though emerging on to the tarmac was like stepping on an ice rink.

Less than 960km (600 miles) below the North Pole, conditions are extreme, with deep snowdrifts and blizzards even in mid-May. For a while, rattling along in a military truck, I could make out nothing but white through the window. 

In deepest winter the temperature drops to minus 50 degrees C and the soldiers occasionally have to head out in their vehicles to disperse the polar bears who amble right up to the base.