We don't need the Canadian Forces to deal with global warming. We don't need the Canadian Forces to deal with most of the threats in the Arctic—some, yes. We will need the Canadian Forces to deal with the threat from China, if it comes to that.
What we need are well-equipped, well-trained, mobile forces that can play a part with our friends in meeting the various threats as they arise--threats to us, where realistically we must rely on the United States for the heavy lifting if there is a direct threat to our territory, because any threat to us is almost by definition a threat to the Americans. The Americans aren't going to seize our territory by force. They may try to exercise influence over us, but I would argue that we achieve the best kind of defence against that by having the capability of actively looking after our own territory.
We count on the Americans for support in a crisis, and that is fine, but we must be prepared to contribute to other parts of the world--UN operations or coalition operations--and that requires a certain kind of capacity.
Again, our first priority should be home defence; the second priority should be North American and hemispheric defence.