[gpm]

Greenland, as part of Denmark, is part of and protected by NATO. As its in the Atlantic it benefits fully from that treaty.

It is also protected by Denmark's membership in the EU and the CSDP by virtue of the EU's collective self defense clause (which protects all of all member states territory, not just the parts in europe).

The status quo - apart from the part where the US is threatening to violate its NATO treaty obligations and invade something it is obligated to protect from invasion - is just fine.