In a filmed address delivered upon his return to Quebec City on Thursday, Carney—who also attended the World Economic Forum in Switzerland—firmly stated: “Canada does not live because of the United States. Canada thrives because we are Canadian.”

Trump's envisioned multilayered “Golden Dome” could include space-based sensors to detect missiles. They could reduce the U.S. need for its Greenland-based radar station, said Marcuz, a former nuclear defense worker for France’s Defense Ministry, now with the Foundation for Strategic Research think tank in Paris.