Canada has been focused on building ships and a port while pondering which CF-18 replacement might be handy way up north. But if the big challenges are ships (research/whatever) and planes, then invest in stuff that thwarts such stuff. While subs are super-handy for denying access in large bodies of water and especially under the water threats, they are also super-expensive and will always be scarce (Canada will never buy enough, sorry).
But missile batteries that aim to knock down planes and sink ships? That can be done at a fraction of the cost. Staffing them? That is harder, but perhaps remote controlled? Or just rapidly deployable? Given how long it takes to get to the Arctic from anywhere by ship (also through straits controlled/monitored by the Americans), one would have plenty of time to move a battery of anti-ship missiles to key spots in the high north. Where? Check out this pic:
|Thanks to Steve Daly, http://www.casr.ca/as-nwp-radar-aerostat-daly.htm|
Of course, for land based ops, there is always this. H/T to Chris Zeitz @PrivateSnuffy