The US supported Panamanian independence from Colombia.
The Panama Canal was built by the US Military for the US Military (to move naval assets between the Atlantic and Pacific Oceans in the wake of the Spanish American War of 1898).
The US needs to re-take control - military or corporate - of the Canal Zone more than it does Greenland.
If CK Hutchison owns the Canal and its port facilities, instead of just operating them, Panama needs to nationalize the Canal to hand ownership/control/operation to the United States.
F Jimmy Carter and the Chi-coms. Wait until the French and British figure that the Chi-coms want the Suez Canal too, if they don't already have it in their clutches.
America needs to move away from Wilsonian Foreign Policy and pivot back towards the Monroe Doctrine.