Iron Man, Vol. 1 #121 (1979)

A Ruse By Any Other Name
Iron Man realizes he's been duped, so he and Namor seek to stop the dupers. When they arrive, Rhodey fills him in on the truth about this "Navy" group: they are Roxxon employees, seeking Vibranium deposits on the island. Unfortunately, sensing their imminent defeat, the Roxxon employees destroy the island, taking the vibranium and evidence of their plan along with it.
Release Date: 1979