A rainbow over the tundra near Esieh Lake in Northwest Alaska. (Jonathan Newton/The Washington Post)

Heather A. Conley is senior vice president for Europe, Eurasia and the Arctic at the Center for Strategic and International Studies in Washington and a former deputy assistant secretary of state in the George W. Bush administration (2001-05).

This week, the American people and the world have become much more familiar with Greenland, the world’s largest island. We know that two U.S. presidents, Harry Truman (in 1946) and Donald Trump (Friday) have expressed interest in purchasing it. President Truman quoted a price of $100 million in 1946; we never learned the figure President Trump had in mind. But the offer was moot before it was proffered: Greenland is not for sale, but very much “open for business,” according to Greenland’s foreign minister and the prime minister of Denmark.

Over the past few days, there have been many questions about the possible motivations behind the president’s interest in and enthusiasm for Greenland. The next bold real estate move? A strategic gambit to bolster U.S. military presence in the Arctic? Or a wily decision to further cement America’s economic dominance? On the latter, the economics of the Arctic are important to understand.

Six years ago, my think tank conducted a study in which we examined the economic benefits of a rapidly transforming Arctic. While we focused on the United States, our report did examine Greenland and its rich mineral resources, which include rare earth elements, uranium, iron ore, gold, diamonds, lead and zinc. Greenland, like Alaska, Canada and Russia, is home to some of the world’s largest nickel, iron ore and zinc mines.

The discovery of large reserves of rare earth metals is what has probably piqued Chinese economic interest in Greenland. Rare earth elements are essential to a range of smartphones and other devices, but they also have critical applications in the defense, automotive and renewal energy industries, including in wind turbines, hybrid-vehicle motors, missile-guidance systems, rechargeable batteries for consumer products, night-vision goggles, alloys for sonar technology and lasers in weapons systems. The Ilimaussaq complex on the southwestern coast of Greenland holds the largest quantities of rare earth elements in the world, with an inventory of 10.3 million tons of rare earth oxide. This same complex also holds 575 million pounds of uranium concentrates, as well as 2.21 million tons of zinc, which would meet a great deal of global demand for the next 50 years. Several Chinese companies are already actively mining in Greenland. The United States has not made any comparable investments in the island.

In 2008, the U.S. Geological Survey estimated that the Arctic could hold upwards of 30 percent of the world’s undiscovered gas resources and 13 percent of the world undiscovered oil resources, with an estimated 84 percent located in offshore areas. While the survey again brought a greater focus on Alaska’s extensive resources, believed to hold the second largest Arctic energy reserves in the world, Greenland also drew attention. So far, however, the envisioned Greenland oil boom has not panned out. In 2013, a British firm abandoned its exploration efforts off the coast of Greenland after its $1.4 billion venture did not yield predicted reserves.

And in a world with a rapidly diminishing Arctic polar ice cap, increased Arctic shipping — both across the Arctic and through the Central Passage or trans-Polar route — could economically benefit Greenland. Investment in port infrastructure and related maritime activity would make Greenland a potential shipping hub for trans-Polar commerce. China is exploring the possibilities of this trans-polar sea route as the Chinese shipping firm COSCO annually tests this route. But Greenland’s small population (57,000) and limited infrastructure (predominantly along the southwestern coast) make it less attractive. Iceland seems to be a more attractive location for enhanced port infrastructure (which a German firm is pursuing) for future Chinese exports.

One of the least discussed reasons that China is interested in exploring economic opportunities in the Arctic is the country’s continued access to the rich and growing fishing stocks in the Arctic. In fact, access to fishing stocks is so economically vital to Arctic nations that they have raised tensions and led to the potential for conflict. One example is the so-called “cod wars" between Iceland and Britain in the 1970s.

With all the discussion about the economic importance of Greenland, the ironic part of this tale is that Arctic mineral and energy resources, key shipping infrastructure and fisheries already exist in the United States today ... in Alaska, a strategic purchase the United States made from the Russian empire in 1867 for a mere $7.2 million. Wouldn’t it be better to wisely and sustainably invest in the American Arctic? The American Arctic urgently needs a deepwater port to responsibly manage an increase in shipping traffic through the narrow Bering Strait. Although it is controversial and must be balanced with strong environmental protection, the United States can enhance its mineral and energy extraction from Alaska while working toward diversifying its resource-based economy. Rather than buy Greenland, I strongly encourage the president to invest in Alaska and deepen our economic and security engagement with Greenland and Denmark. After all, both are open for business.

Read more:

Carl Bildt: Trump’s Denmark saga of the absurd

Dana Milbank: The U.S. must take Greenland by force!

Jennifer Rubin: Trump seems to have lost it. So what do we do?

Alexandra Petri: The Emperor’s New Island, a tale of Trump buying Greenland

Eugene Robinson: Trump is melting down. Again.