The difference here is presumably for the last hundred years, ending last November, there was simply no chance of a invasion of Canada. Nukes might fly overhead and end the world as they struck targets on either side, but other than that we were safe and any significant military action we took part in would be overseas and thus not justify calling up a huge number of reservists.
Meanwhile Norway was occupied in WWII, and after that spent the next decades next to the Soviet Union, and then Russia. There's clearly been a long standing risk of actual invasion.
Meanwhile Norway was occupied in WWII, and after that spent the next decades next to the Soviet Union, and then Russia. There's clearly been a long standing risk of actual invasion.