Usurped power is a phrase common in insurance policies since the 18th century—and still found in standard war exclusions—that refers to an organized military operation, either foreign or domestic, that seizes the powers legally conferred upon a government.
It is distinguished from insurrections and mob uprisings by the requirement that an organized military force must be used. Losses stemming from usurped power, like other related losses attributable to war, are excluded from most forms of commercial insurance.