The only way to accomplish this at scale is to build something that is legit better and let the market decide. Anything else is just principled wishful thinking.
It's hardly rhetoric, from the European perspective. The EU is already embroiled in a proxy war against a major power in Ukraine, and are now faced with the prospect of their strongest erstwhile ally moving to annex EU territory.
Simultaneous war on two fronts, where one opponent is deeply embedded in your supply chains, is an existential threat.
It’s not a completely bonkers idea that the US could purchase all or some of Greenland. In the end, we’ll probably just see a strengthening or enforcement of the existing treaty for US military use of Greenland which is all the US wanted. Europe is still getting used to the president’s rather unique, and yes aggressive, negotiation style born out of his NYC real estate developer days.