The main zones of operation discussed in the plan are:
Nova Scotia and New Brunswick:
Occupying Halifax, following a poison gas first strike, would deny the British a major naval base and cut links between Britain and Canada.
The plan considers several land and sea options for the attack and concludes that a landing at St. Margarets Bay, a then undeveloped bay near Halifax, would be superior to a direct assault on the longer overland route.
Failing to take Halifax, the U.S. could occupy New Brunswick by land cut Nova Scotia off from the rest of Canada at the key railway junction at Moncton.
Imagine, Moncton might have been the key to the British Empire. Though how American politicians would have explained to the public invading a country one-tenth their size, with an army smaller than the New York City Police force, is not explained. Images of anti-war protesters flooding the Mall in Washington with signs reading: "No Blood for Maple Syrup!" or "Coolidge=Kaiser" or "Make Hockey Not War."
The rationale for the plan was that Japan and Britain were allies. In event of war between the United States and Japan, Britain would be at war with America. It's highly unlikely Britain would have risked war with America over the Japanese alliance. It's even less likely the Canadian government would have allowed itself be dragged into an incredibly stupid war. The Canadian defense plan was even more outlandish, we would have launched a surprise invasion of the northern United States.