60% of Canada's population lives in the corridor between Quebec City and Windsor. 80% of the population lives within 2 hours drive of the US border. And 90% of the GDP gets produced in that strip along the border.
The NRDC report named Halifax, Montreal, Ottawa, Toronto, Calgary and Vancouver as the target cities, and with good reason.
Halifax has the world's second-largest natural harbour and is the country's principal Atlantic port. Montreal is the economic heart of Quebec, and biggest port on the St. Lawrence Seaway. Ottawa--the capital and high-tech. Toronto--the HQ of almost everything in Canada. Calgary--oil city. Vancouver--gateway to the Pacific.
Throw in some important secondary targets like Moncton, Quebec City, Hamilton, London, Windsor, Thunder Bay, Winnipeg, Regina, and Edmonton, plus a few more cities that don't immediately spring to mind, and Canada is toast.
Just kidding (sort of). Yes, just like the UK or France, Canada could have had an arsenal of nukes, but we didn't think it was necessary.