I saw the recent hearing where they had on the NORAD chiefs. He was asked directly about the state of it and his reply was there is not a single person from both countries who is not completely dedicated to its continuance. That it is intricately a part of USA defense and nothing will shake that.A relatively small population trying to defend a very large land mass. Russia or China could bite off pieces of Canada with relative ease. I think most sensible people know what prevents that from happening.
Lots of rhetoric but in the end the cooler heads will prevail. Our military alliance is not going anywhere.