Global warming is making both places more important to global shipping and trade. To imagine the kind of future a hotter, dryer climate may bring, and the geopolitical challenges it will create, look no farther than two parts of the world that Donald Trump wants America to control: Greenland and the Panama Canal.

But not everyone is sure that President-elect Donald Trump’s talk of annexing Canada and Greenland and reclaiming the Panama Canal is driven by a deeper strategy.

President-elect Donald Trump took aim at Canada, Greenland and the Panama Canal in a series of Christmas Day social media posts that suggested the United States could take control of all three.