I'm a bit confused by that article. One of the big reasons it says they bowed out of it was due to "effectively allows Washington to decide what to do if a missile was headed toward Canada". By my understanding, the entire program would have been an extension to what NORAD already does. It is a joint operation, manned, funded, and operated by both governments. If something dangerous is spotted, equal amounts of urgent calls go out from Cheyene Mountain to both the US President and Canadian Prime Minister. With the new program, the same processes would occur, and some magical system could then be used to shoot the missles out of the sky.

It seems to be much more a political approval move then anything else, since the article talks about how unpopular the plan was with the Canadian people, and how somehow the program would have decreased the sovereignty of Canada. It doesn't seem the Canadian people will pay less taxes over this, since a 10.5 billion over five year increase was approved for the military there.