“This isn’t the 15th century,” said Peter MacKay, then foreign minister of Canada, on CTV television. “You can’t go around the world and just plant flags and say, ‘We’re claiming this territory.’”

Nixon was careful to say that Russia’s Arctic military activity remains well below Cold War levels, and he dismissed the idea of potential land grabs or invasions. The cold is too intense, he said, the ice pack still vast and thick, the polar distances enormous. Planting a flag at the bottom of the sea is one thing. Sending troops across the ice is quite another.