Uncanny X-Men #150 Newsstand

I, MAGNETO...  Magneto gives the world’s governments an ultimatum. They are to relinquish all governing power to him or he will destroy the world. When a Russian submarine attacks his island, he destroys it and the uses his new machine to create a volcano under a Russian town. His prisoners, Cyclops, who is powerless thanks to another device of Magneto’s, and Lee Forrester decide they must stop him, though they don’t yet know how. In the meantime, the X-Men have been searching the area in their plane, looking for the disappeared Scott. When they fly over the island, the forcefield causes the plane’s controls to go haywire and they crash into the ocean. Without Magneto noticing, they join up with Cyclops and Lee. While their powers are gone, Cyclops reminds them that they still have skills...