With a POD like my NZ/Australia challenge, which is either before WW1 or WW2, somehow have Canada attack the US. Perhaps, SOMEHOW the US becomes a Central Power in this, and so Canada being the closest colony to the US, Britain orders it to attack the US?
PS: Do you guys think Canada would get stomped if tried for SOME reason to attack the US now?
Ok, I can do a realistic mini-TL but there are some serious issues that must be worked out or this would be seriously ASB.
Why would America support Germany? America has closer ties with Britain and France than Germany and Austria-Hungary
Also, Britain and France were unofficially allies with America during World War 1 before official US involvement.
Maybe a Zimmerman-Note like offer from Germany to USA, and since that sounds least ASB-like, I will go from there.
May 1915:
Germany has lost all hope for a quick victory against France, Austria still has land occupied by the Russians in Galicia, and the Ottoman Empire faces two invasions simultaneously. Germany needed a new and powerful ally, and found it in isolationist America. On May 12, a handwritten note was delivered by submarine from Germany to Washington, DC hoping to convince the US that Britain was America's true enemy and that Britain could send spies and partisans through their porous northern border to attack Americans. This message is intercepted by the British Navy (who damaged and beached the sub), and the British were outraged. Accusations flew, and the Canadians thought that the US and Germans were ALREADY working together.
Britain gives the order for Canada to attack the United States, and that Royal Navy assistance would be provided. On May 20, the Canadian Army, pours across the northern border and invades the United States.
Canada's army consists of four army groups: the Pacific Army, the Western Army, the Central Army, and the Eastern Army. Their objectives are Seattle, Billings, Minneapolis, and Syracuse.
Bellingham Washington, , Havre Montana, International Falls Minnesota, and Buffalo New York are taken within days. Fort Lewis (Seattle/Tacoma) and Fort Drum (New York) send out soldiers as soon as the invasion begins. The US begins a defense in depth strategy, sacrificing Great Falls and Duluth so that the Canadians can meet an organized, well controlled defense. The Canadian Army is routed north of Seattle and Minneapolis and west of Rochester. The largest Canadian invasion force defeats the weakest US defense force, and Billings, Montana is also occupied.
However, the Canadian military strategists forgot one important detail; heavily armed civilians who did not want any foreign occupation and knew the land and how to use their guns. Canada's Western Army is stretched thin holding Billings, and after constant partisan attacks, they try to retreat to Canada. The Western Army is being withered down, and (with limited US military intervention), the Canadian Army, surrounded in Great Falls, surrenders to American guerrillas on June 2. They are kept in the city, and formally surrender to a nearby US Army general the next day.
On the Pacific coast, the Canadians attempt to dig trench systems around Everett and be supplied by the Canadian Pacific Navy, but they are flanked from the north by US defense units (really partisans with some Army units), and the US Pacific fleet engages in battle with the Canadian fleet in the Strait of Juan de Fuca on May 25, with both fleets heavily damaged, but the Canadians surrendering. The US Navy sails into Puget Sound and bombards the Canadian trenches without return fire (No heavy artillery was brought by any Canadian army, because they were trying to take land, then scorched-earth retreat their way back to Canada). After seeing that any hope for a rescue or breakout is gone, the Canadian Pacific Army surrenders on May 30.
Will continue to update soon!