10K were stationed there during the Cold War.
"The 1951 Treaty did not account for bringing in a technologically advanced Arctic Defense System." Idiotic. It allowed the US to deploy however many troops and tech to Greenland as it saw fit. During the Cold War we had all sorts of sophisticated radar equipment there.
Let's pretend for a minute that there will be a "golden dome" (there won't). The 1951 treaty covered all of it.
You're out of your league. Not that such things ever stopped you from spewing.