For the past century, the United States and Canada have been the best of friends, and war between them was unimaginable. Before that, however, it was a possibility that was always at the back of mind for military strategists on both sides of the borders—in no small part because the two had gone to war before.
Today, however, anxieties have flared. President Donald Trump has spoken openly about extending the borders of the United States all the way to the high Arctic, insisting that Greenland would be safer as a U.S. territory, while Canada could join the union as the 51st state. This will happen, Trump insists, through peaceful means.
