https://www.politico.com/magazine/story/2018/06/21/that-time-the-us-almost-went-to-war-with-canada-218881/

https://nationalinterest.org/blog/reboot/how-united-states-planned-invade-canada-198457

https://www.businessinsider.com/heres-how-the-us-planned-to-invade-canada-2015-10

https://en.wikipedia.org/wiki/War_Plan_Red