Thank you.
Not only is this a legal issue, it's also a law enforcement issue.
That's the big question. You can have whatever law you want, but if you can't enforce it, it's irrelevant. As mentioned, China is going after lawfare and trying to undermine international rules and regimes, which is what we saw in Scarborough Shoal.
We can't rely on just having a law to protect sovereignty. We need to be able to enforce it. In the Arctic, the U.S. icebreaker fleet is heavily degraded.
As you said, Canada really doesn't have what it needs to defend itself. Russia and China combined are much more powerful, and they will use that advantage if it's in their interest to do so.