yeah, well... The US formerly didn't care about this border because passage-wise it was a dead end for most of the year. That is changing and both nations are aware of it, whichis why Russia is militarizing their side while the US still seems to sleep on it aside from Trump want to annex Canada.

There is actually a huge gap in the US defense where crossing is the easiest.
https://www.operationmilitarykids.org/military-bases-in-alaska/

Almost aa if the Pentagon doesn't care about Alaskans...
¯\_(ツ)_/¯