Conspiracy theorys, where do you stand?

[Telemark]

I suspect there are lots of concerns about spies/ information leaks. Harder to reduce this with another country involved or worse with a group of countries like NATO.

That's a good point, and a reasonable concern. Norway is crawling with Russian spies. Greenland is almost as strategically located as Norway for the Russians. And Greenland is one of the most strategically important locations for the US vis-a-vis intercepting ICBMs.

Denmark is an ally, but it's just too small to properly administer and defend a landmass the size of Greenland.