Jamieson, Fausset and Brown on Revelation 18:10

10. God's judgments inspire fear even in the worldly, but it is of short duration, for the kings and great men soon attach themselves to the beast in its last and worst shape, as open Antichrist, claiming all that the harlot had claimed in blasphemous pretensions and more, and so making up to them for the loss of the harlot.

mighty--Rome in Greek means strength; though that derivation is doubtful.