The British Military of the Cold war era trained to counteract the real threat of Russian invasion into any vulnerable Country of NATO. The Royal Marines enthusiastically took on the role of Arctic Warfare troops in the Northern Flank of Norway becoming experts in this field. The idea was to deny the Russia submarine fleet the Norwegian fjords which would have prevented USA reinforcement of Northern Europe.
How did NATO and the British Military implement this? Well they sent The Royal Marines downhill skiing in Norway for three months each year, military skills were further enhanced with sailing all over the world and any sporting activity encouraged. Occasional bouts of slightly active service in Northern Ireland kept internal security skills alive but the big one was the Falklands Islands invasion by Argentine forces in April 1982.
Royal Marines easily adapted Commando and Arctic warfare skills to not only survive the elements of a harsh South Atlantic winter but to excel and overcome a vastly numerically superior army 8000 miles from the UK. 42 Commando Royal Marines played a significant part in the conflict and perhaps pulled off one of the most successful Battalion sized attacks since World War two on Mount Harriet.