President-elect Trump's talk of Canada as a "51st state" and annexing Greenland registered among national-security crowds as an "Oh, boy!" moment. Obnoxious, enticing, familiar. Why it matters: The darlings of Trump's current foreign policy fixation boast Arctic utility at a time when the icy region is heating up.

The frosty island sits atop giant oil and gas reserves that climate campaigners say must never see the light of day.