Greenland

Jared Diamond suggests that cultural practices, such as rejecting fish as a source of food and relying solely on livestock ill-adapted to Greenland's (deteriorating) climate, resulted in recurring famine which led to abandonment of the colony. However, isotope analysis of the bones of inhabitants shows that marine food sources supplied more and more of the diet of the Norse Greenlanders, making up between 50% and 80% of their diet by the 14th century.
Especially during the Cold War, the United States developed a geopolitical interest in Greenland, and in 1946 the United States offered to buy Greenland from Denmark for $100,000,000, but Denmark refused to sell. However, in 1950 Denmark did agree to allow the United States to establish the Thule Air Base, construction of which was begun in 1951 and completed in 1953, as part of a unified NATO Cold War defense strategy.