It’s a bit more complicated than that I think. It was a NORAD response and that has a fair amount of integration between US and Canada. The base the American jets flew from has Canadian air force pilots stationed there—and is a western norad air defense post, so likely they are closest responding, and the Canadian hornets were coming from farther out (possibly Alberta?). But operationally the request came from a NORAD division in Canada, so it wasn’t like the US Air Force deciding to unilaterally violate Canadas sovereignty over a rogue Cessna. More like joint operation under mutual defense treaty kind of stuff like you’d get with NATO countries.

I don’t fully understand exactly how it all works but back in the pandemic a us F-22 shot down a spy ballon in Canada also I think, run via NORAD also. Canada maintains a lot of the northern radar and early warning stuff that NORAD uses as well.

Anyhow I wouldn’t blame Canadians for not being thrilled about American military assets zipping around overhead right now, just saying it’s not specifically remarkable as the article headline seems to suggest.