canada's attempt to control the northwest passage as a purely "internal waterway" is inconsistent with international law and doomed to failure.
rather, the international law on the topic should lead to an agreement similar to the one that governs the bosporus, where the turks maintain some rights to inspection but ultimately are forced to allow for free passage.
a reasonable person would ask the following reasonable question: is there a way to travel between greenland and alaska (or russia) without transiting canadian waters? and, there is not actually a way to do this. it would not be reasonable to conclude that, because there is no way to do this, canada should benefit from the ownership of the straits; rather, a reasonable person would recognize that our monopoly over the area requires us to allow access to passing vessels, subject to very limited and measured expressions of sovereignty. and, we are expected to behave reasonably.
the issue of resource exploration is a different one, and we are on much firmer ground there, although we shouldn't actually exploit it.