Greenland's strategic importance
The Trump administration's recent push to purchase Greenland from Denmark raised a number of questions and generated more than a few healdines. One thing we learned was that the Truman administration sought to purchase the world's largest island back in 1946.
That sale never happened, obviously. But if the topics resurfaces, the Congressional Research Service has assembled a briefing paper on U.S.-Danish relations and the Greenland issue, specifically. It makes for fascinating reading:
The United States considers Greenland strategically important and has maintained a military presence in Greenland since World War II. During the Cold War, Greenland played a key role in U.S. and NATO defense strategy. Thule Air Base in northwest Greenland is the U.S. military's northernmost installation, providing 24/7 missile warning and space surveillance. Thule also hosts a deepwater seaport and airfield. Warming temperatures in the Arctic and ice loss in Greenland pose environmental concerns but also raise the possibility of increased access to Greenland's potential oil, gas, and mineral reserves (since the 2009 Self-Government Act, Greenland has assumed the right to utilize these resources). In 2013, in a controversial effort to diversify its fishing-dominated economy, Greenland repealed a law banning the mining of radioactive materials and rare earth minerals.
Many U.S. policymakers and experts are wary about increased Russian military and commercial activity, as well as Chinese investments, in the Arctic. Some believe that China views Greenland as key to increasing its influence in the Arctic. In 2018, the prospect that China's state-run banks and a Chinese construction company might fund and help build or upgrade several airports in Greenland alarmed U.S. defense officials; the United States reportedly expressed its security concerns to the Danish government, which ultimately announced it would help finance the airport projects instead.
You can read the entire CRS briefing paper here.