Canada had a defence industry with 1st class fighter jets being developed. The U.S. insisted on it being shut down as they didn't want an independent well armed neighbour. Canada is heavily integrated into norad - it doesn't spend the same proportionally as the U.S. on military but that's because it doesn't partake in the global military power projection like the U.S. so much. if you look at what the U.S. spends on actual defense of homeland, Canada's proportional spending is close.

This is one of those talking points that if you took just a second to Google you'd see is just one of the many things Trump says that's bullshit.

Canada spends both in actual dollars and % GDP about the same as Australia (another commonwealth nation) more than Spain, the Netherlands, Mexico (yet they don't get these Trump talking points as the southern neighbor), Taiwan in actual dollars (a nation under threat) etc. Canada historically known as a peacekeeping nation and yet still spends 16th in the world in military spending.

The comparison is apples and oranges because the US significantly overspends and does so with the direct purpose of exerting power and pressure globally to serve their political and financial interests. NO ONE has "a leg to stand on" as a dollar for dollar comparison to the US because they're spending a trillion dollars annually. They account for nearly 40% of the entire world military spending to the point that adding up the next like 9 in spending still doesn't equal that. Now imagine if they cut that by 25% how much good that would do for the average American while still maintaining dominance in the military space globally.

Backwards country complaining almost no one else is backwards too.