Sharon J.'s marriage at age 14 in Tanzania dashed her hopes for the future: “My dream was to study to be a journalist. Until today, when I watch news or listen to the radio and someone is reading news, it causes me a lot of pain because I wish it were me.”

Around the world, marriage is often idealized as ushering in love, happiness, and security. But for Sharon and other girls, getting married is often one of the worst things that can happen. Roughly one in three girls in the developing world marries before age 18; one in nine marries before turning 15.

Human Rights Watch investigations in Afghanistan, Bangladesh, Malawi, Nepal, South Sudan, Tanzania, Yemen, and Zimbabwe have found that early marriage has dire life-long consequences—often completely halting or crippling a girl's ability to realize a wide range of human rights. Leaving school early both contributes to, and results from, marrying young. Other impacts include marital rape, heightened risk of domestic violence, poor access to decent work, exploitation doing unpaid labor, risk of HIV transmission, and a range of health problems due to early childbearing.

At present, unprecedented attention is being paid to child marriage globally. Prominent voices in and out of government—including those of Sheikh Hasina, the prime minister of Bangladesh, and Joyce Banda, the former president of Malawi—have publicly committed to fight child marriage in their countries.

But change is often incremental, and promises do not always lead to effective action. Despite setting a goal of ending child marriage in Bangladesh by 2041, Sheikh Hasina has also proposed legislation that would lower the age of marriage for girls to 16 from the current age of 18. In April 2015, Malawi adopted a new law setting the minimum age of marriage at 18; however, it does not override the constitution, which does not explicitly prohibit child marriage under 15, and allows 15- to 18-year-olds to marry with parental consent.

International donors, United Nations agencies, and civil society groups, including Girls Not Brides, a coalition of more than 500 organizations worldwide, have also rallied behind the cause. The challenges are formidable. Child marriage—fueled by poverty and deeply rooted norms that undervalue and discriminate against girls—will not disappear if the concerted attention it now enjoys subsides in favor of the next hot-button issue.