Photo by AP Photo/Darren Hauck

Milwaukee Mayor Tom Barrett, injured after intervening in domestic violence custody dispute.

Chances are, we'd never have heard of Anthony J. Peters, a 20-year-old thug, if he hadn't beaten up Milwaukee's mayor last week outside the Wisconsin State Fairgrounds.

If Peters had pounded and pummeled and bullied his intended victim -- the grandmother of his 1-year-old daughter -- he'd have been just another assailant in a long list of men who terrorize women every day of the week.

But it was Milwaukee Mayor Tom Barrett who stepped into the fray when he heard the woman's call for help. Peters had taken her cellphone, and she was crying out to people in the crowd, begging them to call police.

Barrett stepped forward, according to reports, and was asking Peters to calm down when Peters turned on him. Barrett, 55, used his body to shield the woman and baby. He took the blows, the punches, the unleashed violence in their stead.

When police arrived on the scene, the mayor was lying in a pool of blood. Peters had beaten him with a metal pipe, fracturing the mayor's arm, cutting his face and head, hitting him with such force that he knocked out some of Barrett's teeth.

Had the woman been the one beaten, the assault would have been one more line in a police log -- time, date, domestic violence call -- unless he'd killed her or the child. But because it was the mayor who bore the brunt of the violence, it made headlines.

And his actions forced a conversation about domestic violence this nation continues to avoid, at great cost.

Through the week, we heard these updates: Peters, who has an extensive record of violent behavior, was taken into police custody. His relationship with his ex-girlfriend, who is the mother of the 1-year-old at the fair, is complicated and messy. Neighbors report that he stalked her after their breakup, standing outside the house, watching her every move. Friends say he was "desperate." Peters wrote on Facebook that "everyone has a story to tell" and his was going to end either in death or prison.

Barrett was released from the hospital after surgery and was back to work by midweek, issuing thanks to his niece for making the 911 call and praising the police for quick action. He deflected all praise. He said it was simply the right thing to do.

The rest of us were left asking ourselves a string of questions: What would we have done in Barrett's situation? Would we have looked the other way when the woman begged for help? Figured it was none of our business? That whatever the dispute, it was between the man and the woman? That it appeared to be too dangerous to intercede?

All good questions, soul-searching questions, important questions. But the one that really begs to be asked is: How do we end domestic violence?

For years, the quest was seen as the exclusive domain of women, a cause borne out of the women's movement -- but lately, the tables have turned. Experts say there will never be an end to the epidemic of domestic violence until men begin to hold other men accountable for their actions.

Until, in effect, men say to one another: Knock it off. Violence is never the answer.

That's what Tom Barrett did last week, if not in specific words, certainly by his action and intervention. And when he stood in front of the cameras a few days later at his first press conference, his face bruised and cut, his arm in a cast?

His image was a powerful reminder of the 5.3 million women who are the victims of domestic violence every year.