"Leap in to the breach" is often used to describe the action of courageously entering into a difficult or challenging situation. There are several synonyms that can be used to convey a similar meaning, such as "step up to the plate," "rise to the occasion," or "take the bull by the horns." All of these phrases imply a willingness to confront difficulties head-on and to provide swift and decisive action in the face of adversity. Other synonyms for "leap in to the breach" might include "take charge," "seize the moment," or "grasp the nettle," all of which suggest a sense of bravery and resoluteness in the face of challenge.