They 'swore' (an oath of) allegiance to the United States of America. [=they formally promised that they would be loyal to the United States of America]
He 'swore us to secrecy/silence'. [=he made us promise not to tell anyone his secret]
He was so disgusted by the election results that he 'swore off' politics for good.
(..) Good-bye, khaleesi. Do not walk away from your queen, Jorah the Andal. You have not been dismissed. You pledged yourself to me. You swore to obey my commands for the rest of your life. I command you to heal yourself When I take the Seven Kingdoms, I need you by my side. In the last fortnight since (..)2016 TvShow: Game of Thrones Title: The Door Season: 6 Episode 5