We protect and counsel the victim of the bully as our first and most important priority, yet also seek to counsel and solve the stress-puzzle of the bully.
A bully is a person with developmental damage to their prefrontal cortex - they didn't develop sufficient empathy and self control.
Bullying is a symptom of stress in a brain not mature enough to disperse it in a healthy way. Thus we need to treat the cause - the stress - rather than keep on endlessly addressing symptoms in infinite ways.
The hero takes the punch for a friend when they could easily step aside; the bully throws the punch they could easily choose to make an open hand of friendship. Decide who you are.
Humans are a mammal that learns best from role modelling - observe, practice, imitate, master. Thus how we adults deal with stress as (the cause of bullying) will have the greatest impact on how youth and children deal with it. To make a new more positive cycle of behaviour, we have to change our own instead of preach.