Thank you very much for this excellent question.
I think Canada and the United States have agreed to disagree on some of the sovereignty issues. We seem able to collaborate and co-operate without having agreed on the actual territorial boundaries.
The U.S. is not a signatory to UNCLOS, as I understand. However, I would like to reiterate what I said earlier. The U.S. is obviously critical to the protection of the Arctic. We recognize the importance of NORAD. We are finally getting around to doing more to support NORAD, but we really need to step up in our collaboration not only with the U.S. but with the other partners I mentioned. That's because even though other countries are not going to be claiming land, they have the potential to help in the development of the Arctic.
We also have to counter.... Don't forget that Russia is also significantly interested in the Arctic for obvious reasons, as is China. It's the rest of us who will have to ensure that the Arctic is protected and developed as necessary.