Who will be dumb enough to believe American security promises anymore? America won't defend anyone no matter what they promiss.
If they wanted to sell defense, threatening annexation of countries they are supposed to have current defensive arrangement with is inconsistent with that. Allying yourself with Russia is inconsistent with that too.
And above all, an attempt to use past help as a reason to make the other country your colony for materials extractions while trying to sell their parts to Russia ... makes you untrustworthy.
Greenland is not threatened by China right now, they are threatened by America.
If they wanted to sell defense, threatening annexation of countries they are supposed to have current defensive arrangement with is inconsistent with that. Allying yourself with Russia is inconsistent with that too.
And above all, an attempt to use past help as a reason to make the other country your colony for materials extractions while trying to sell their parts to Russia ... makes you untrustworthy.
Greenland is not threatened by China right now, they are threatened by America.