Donald Trump’s gambit to buy Greenland may sound ridiculous, but it’s not impossible. If the president-elect is really determined to control the world’s largest island, he could try to buy it outright if the autonomous territory declares independence from Denmark.

President-elect Donald Trump left open the possibility Tuesday that he might use military force to take over the Panama Canal and force Denmark to sell Greenland to the United States, and said he could use “economic force” to make good on his bizarre proposition of annexing Canada.