Naval News reports on a Webinar conducted by Admiral Robert Burke who is Commander of U.S. Naval Forces Europe, Commander of U.S. Naval Forces Africa, and Commander of Allied Joint Forces Command in Naples. Previously he served as Vice Chief of Naval Operations. He is a submariner. Sounds like he spent some time under the ice.
There is a lot here about the Arctic. Keep in mind he is talking primarily about the Atlantic side rather than the waters around Alaska. This is primarily about the Russian threat, but there are concerns about China as well.