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.
(..) We have new members here? Believe so, sir. Put their next round on me. Got you, sir. No, no, no, no. Last time I played Pebble I swore I'd never pick up another club again. Speaking about games... Couldn't help but overhear you talking about CRS. Well, the reason I mention it is I took the (..)1997 The Game