Americans will be too busy trying to keep their own country together than to worry about invading Canada. Fact is, the National Guards of the American States are probably more powerful and stronger than the US Army is on American soil. Some Guard units even have advanced fighter jets. The National Guard troops are a substantial component of the strength of the American army. The American army would have to bring all of its own assets back from the rest of the world before they could even contemplate military action on American soil.
And the National Guard units answer to State legislatures, not Washington.
https://www.usamm.com/blogs/news/who-controls-the-national-guard-when
The primate in that movie was every bit as obnoxious in real life as it was in the movie. The handlers had their hands full with that one. Lots of work for the costumer who had to do the laundry.
But that tennis ball on a stick was actually part of the stock publicity footage. I remember viewing it as well.