As it turns out, Katz isn’t the first Canadian to speculate on how to fight the U.S.A. In fact, Canadian military strategists developed a plan to invade the United States in 1921 — nine years before their American counterparts created War Plan Red.
The Canadian plan was developed by the country’s director of military operations and intelligence, a World War I hero named James Sutherland “Buster” Brown. Apparently Buster believed that the best defense was a good offense: His “Defence Scheme No. 1” called for Canadian soldiers to invade the United States, charging toward Albany, Minneapolis, Seattle and Great Falls, Mont., at the first signs of a possible U.S. invasion.
“His plan was to start sending people south quickly because surprise would be more important than preparation,” said Floyd Rudmin, a Canadian psychology professor and author of “Bordering on Aggression: Evidence of U.S. Military Preparations Against Canada,” a 1993 book about both nations’ war plans. “At a certain point, he figured they’d be stopped and then retreat, blowing up bridges and tearing up railroad tracks to slow the Americans down.”
Brown’s idea was to buy time for the British to come to Canada’s rescue. Buster even entered the United States in civilian clothing to do some reconnaissance.
It was not immediately apparent, in the wake of World War I, that the United States and the United Kingdom would remain allies. The United States, after all, had entered World War I as an associated power. The United Kingdom maintained an alliance with Japan, which the United States viewed as our most likely foe. The jockeying for power between Japan, the UK, and the US resulted in the Washington Naval Treaty, which abolished the Anglo-Japanese alliance and limited the naval procurement of all three countries.
The Naval Treaty was not Britain’s only strategic option, however, and the Dominions played a role in pressing London toward the multilateral option. Tensions had run high between the US Navy and the Royal Navy during the war (some US admirals were reluctant to commit a squadron of battleships to the Grand Fleet, believing that the British would somehow manage a confrontation between the US ships and the German High Seas fleet, to the detriment of those two navies and the advantage of the UK), and relations between the IJN and the RN were quite close. In 1920 the Royal Navy enjoyed roughly the same level of advantage over the US Navy as it had over the High Seas Fleet, and a combination of Japan and the UK would have had a clear naval superiority over the US.
To the Australia and Canada, which had given virtually unconditional support to the British during the war, the idea of an Anglo-Japanese alliance against the US was unpalatable. The Australians did not wish to see Japan dominate the Pacific. The Canadians realized that, in spite of British superiority at sea, war against the US would result in the end of Canada. Even if the Royal Navy could defeat the USN, it could not hope to transport or supply an expeditionary force large enough to defeat the US Army.
There were other reasons, too; the British suspected that the US might, in the long run, be able to outpace BOTH Japan and the UK in naval construction, and very few in the UK wanted to pay the cost of an arms race with either power. Nevertheless, it’s interesting that the threat of a US invasion of Canada played some part in global political dynamics as late as the 1920s.