What would be interesting to review would be the various results of the war games played by the Naval War College in the 1920’s and 30’s which were used to develop Plan Orange (the contingency plans for war with Japan). Were the Naval planners of the that period projecting that the Japanese could invade the west coast of the USA?
As it turns out, there was a plan that concerned an invasion of the US West Coast by a foreign power – but by Great Britain in War Plan Red. War Plan Orange did not anticipate an invasion by Japan.
The U.S. military really did develop a “Joint Army and Navy Basic War Plan–Red” in the 1920s and ’30s, and it really did include provisions for an invasion of Canada by the United States.
The document was declassified in 1974, so this isn’t really a new story, but there has been some hoopla about it lately. Concerns in some quarters notwithstanding, the whole thing was just a theoretical exercise in military planning. The brass would have made better use of their resources planning for a war with Germany, but that wasn’t politically expedient. They reasoned that planning for unlikely wars was better than no planning at all. War Plan Red was never intended to be put into action except in the event of a war with the United Kingdom, an eventuality that everyone would agree was highly unlikely after about 1900.
In the color codes used at that time, “Red” referred not to Canada (that was “Crimson”), but to the United Kingdom. The proposed invasion of Canada wasn’t an end in itself; it was just the easiest way to hurt the U.K. The plan called for quickly seizing the key port of Halifax to prevent British resupply; cutting communication between eastern and western Canada by capturing Winnipeg; securing bridgeheads near Buffalo, Detroit, and Sault Ste. Marie; and attacking Quebec overland from New England. If everything went according to plan, the U.S. military hoped to take the Great Lakes region and St. Lawrence valley before moving on the prairies and British Columbia. Later when U.S. naval forces were built up, they might be able to take Bermuda and Britain’s Caribbean possessions on the road toward victory.
But there would be a price to pay for any such war. Planners essentially wrote off the Philippines, Guam, and Samoa if the British tried to take them early in the war. Planners also anticipated a possible invasion of the U.S. Pacific coast by an allied force from Britain, Australia, and New Zealand.
Now, given that War Plan Orange did not anticipate an invasion of the West Coast by Japan, why would War Plan Red have anticipated one by the Commonwealth? The answer, as always, comes down to logistics. The Royal Navy had the ships to deliver a large force to US shores while the Japanese did not. You’ll note that both Orange and Red anticipated the loss of the Philippines; its actual fall could have come as no surprise. As I mentioned previously, the decision to defend the Philippines was primarily political and the Navy wisely opposed it from the start.
Needless to say, this should demonstrate the vast divergence that often exists between what the public believes and what the planners know. A good lesson for our times.