After World War I, Canada drew up classified plans to invade the U.S. Meanwhile, the U.S. had its own secret plot to create the “United States of North America.”
I never knew 1921 to 1930 was such a frosty time in Canadian-U.S. relations that BOTH sides drew up possible invasion plans. Judging by these amazing arrows, these plans were never seriously about to be executed, but it is a good reminder that geopolitical partnerships (and rivalries) are ever-changing. Today, if there are border tensions between these two allies, it might just center around the Arctic as it’s geopolitical importance is rising. Also, I did enjoy the 1920s reference that Americans simply assumed that Canada (once the British Empire was dismantled) would naturally be absorbed by the United States.