As various commentators have pointed out, do not take Trump literally, but absolutely take him seriously. Threats to Canada and Greenland are part of the chaos and distraction play. The actual project in progress is the crippling and/or destruction of the large Federal institutions that have provided stability to the practical governance of the USA to date. The inertia of these institutions is what got us through the first Trump term with minor damage (as well as various earlier wobbles in "democratic" stability).

The takeover of a nation-state by other than pure military force requires first of all significant destabilization and/or dismantling of the existing institutions of government and governance. The resulting instability (chaos and fear) creates optimal psychological conditions for implementing an authoritarian regime. Whether that regime will still want to subjugate Canada and Greenland is irrelevant to preventing that regime from existing.