Ending violence against women is not the work of a day or even a year. It will require concentrated efforts on many fronts with governments, non-profit organizations, and citizen leaders all pulling together. Most importantly, it will require fully tapping the largest and most natural group of allies women have: men.

One in three women around the world will experience gender-based violence in her lifetime. In some countries, that number is as high as 70 percent. Whether it happens behind closed doors or as a public tactic of intimidation, violence against women has consequences for the entire community - men and women alike.

When women are abused, businesses close, incomes shrink, families go hungry, and children grow up internalizing beliefs and behaviors that perpetuate the cycle of violence. A community that is unsafe for women is unsafe for everyone. On the other hand, protecting and educating girls contributes to economic growth and helps entire countries prosper.

So men and boys have an interest in ending violence against women. They are also uniquely positioned to help do it. In societies where women are marginalized, men can make the case for nonviolence and gender equality. They can challenge harmful cultural practices that enable gender discrimination.

I often say that we need to empower women because no country can make economic progress if it leaves half the population behind. It's just as true that no country can stop violence against women with the other half of the population sitting on the sidelines.

There are stories from all over the world demonstrating how men and boys can get involved and speak out against gender-based violence. One group based in Senegal, Tostan, has taken this approach to changing the dangerous custom of female genital cutting. This severely painful practice can cause hemorrhaging, infection, increased risk during childbirth, infertility, or even death.

Tostan learned that abandoning this centuries-old tradition needed to be a collective and community-led decision with the participation of male leaders. So they organized a discussion for the entire village where men and boys could hear their mothers and sisters describe the pain and health problems associated with it. Eventually, the village voted to end the practice.