The United States Coast Guard is an armed fleet. It is actually one of the largest navies in the world. In wartime it operates under the Pentagon, and in peacetime it's under—I'm not sure—the Department of Energy or something. It is an armed fleet, and that's the main distinction, really, between the Canadian and American coast guards.
I believe that the U.S. Coast Guard is responsible for addressing threats out 500 miles, whereas in Canada we have a mixture of agencies involved in maritime regulation. There is the coast guard, but it would be the navy that would be 400 miles or 500 miles offshore. Their way of doing things is conceptually a lot easier to think about, because they have just the coast guard dealing with things close in—within 500 miles of the continent—and then they have U.S. Northern Command and NORAD doing air and the land component.
It would make sense for Canada to go in that direction.