burn one's bridges

Idioms and Phrases

Also, burn one's boats . Commit oneself to an irreversible course. For example, Denouncing one's boss in a written resignation means one has burned one's bridges , or Turning down one job before you have another amounts to burning your boats . Both versions of this idiom allude to ancient military tactics, when troops would cross a body of water and then burn the bridge or boats they had used both to prevent retreat and to foil a pursuing enemy. [Late 1800s] Also see cross the rubicon .