During a frozen morning in Arctic Norway, a group of British and Norwegian soldiers padded softly through a snow-blanketed birch forest. They were on a simulated NATO reconnaissance mission, among some 30,000 troops who took part in a drill rehearsing a counter-attack against an invading “enemy to the east,” a euphemism for Russia, Norway’s Arctic neighbor. Russia has raced far ahead in Arctic defense over the past decade, modernizing the world’s largest ice-breaking fleet as climate change