Greenland is technically the world's largest island. Located at the top of the world, just east of Canada, it is geographically part of North America but has been politically and culturally associated with Europe for more than a millenium. While a large land mass, three fourths of it is covered by ice so it is also the least densely populated country in the world.
In the early 1900s, a dispute arose over who controlled Greenland--Norway or Denmark. The case was submitted to the Permanent Court of International Justice in 1933. The court ruled in Denmark's favor. In 1953, Greenland was made an equal part of the Danish Kingdom. Home rule was was granted in 1979.
After WWII, the United States developed a geopolitical interest in Greenland. In 1946, they offered to buy the country from Denmark for $100 million dollars. Denmark refused to sell though. They did, however, allow the US to reopen Thule Air Base in 1950. And from 1951 and 1953, the base was greatly expanded as a part of a NATO Cold War defense strategy.