How did suppporters of us expansion justify increased involvement in world affairs by the US of America?

Supporters of U.S. expansion justified increased involvement in world affairs through the ideology of Manifest Destiny, which held that it was America's divine right and duty to spread democracy and civilization. They argued that expanding U.S. influence would promote economic interests, secure new markets for American goods, and enhance national security. Additionally, proponents often framed American expansion as a moral obligation to uplift "backward" nations and promote progress and stability globally.