Nigerian President Goodluck Jonathan signed a bill this week that criminalizes female genital mutilation or cutting, a practice that a staggering 19.9 million Nigerian women are thought to have undergone. The landmark legislation is being hailed as an important step for Africa’s most populous country but also one that experts hope will have a potential ripple effect on the 26 other African nations that have significant populations of women who undergo the practice.

Nigeria’s decision to outlaw female genital mutilation (FGM) sends “a powerful signal not only within Nigeria but across Africa,” according to J. Peter Pham, the director of the Africa Center at the Atlantic Council. “Nigeria, just because of the sheer size of its population, has one of the highest absolute number of cases of FGM in the world,” he said, adding that the bill now effectively criminalizes a significant percentage of FGM on the African continent. “One cannot overestimate the impact of any decision by Nigeria [on the continent].”

More than 125 million girls and women around the world are estimated to have undergone some form of FGM, with the majority concentrated in 29 countries, all but two in Africa, according to a 2013 study by the United Nations Children’s Fund (Unicef). FGM, also known as female genital cutting or female circumcision, is a procedure in which all or most of the external female genitalia is either removed or otherwise surgically altered for nonmedical reasons. The procedure has no documented health benefits and is considered a violation of the human rights of girls and women by international bodies like the World Health Organization.

Despite international efforts to rout the practice, FGM has prevalence rates of as high as over 95 percent in countries like Somalia, Guinea, Djibouti and Egypt. In Nigeria, which has a population of 175 million, the national prevalence is estimated at around 27 percent, with considerable variation across regions, the highest of which is represented in the southern portion of the country. The continued prevalence of the procedure is a result of deeply ingrained cultural and social factors. This has posed a challenge both for international health and rights advocates as well as national and local players who have sought to end FGM.

In this regard, the timing of Nigeria’s decision to outlaw the procedure is no coincidence. While advocates have campaigned for this legislation for over a decade, it was only passed this week, in the final days of the Jonathan presidency. “There's a price to be paid by bucking norms that are widely observed,” said Pham. “It took a lame duck president and lame duck legislators who don't have to face voters to undertake something that goes that much against the cultural norms or practices.”

Indeed, Pham argued that Jonathan has even done a favor for his successor, President-elect Muhammadu Buhari, who will now not have to face future voter backlash by legislating the controversial issue. “It's already signed and Buhari can say he's simply enforcing the laws,” he said.

As momentous as this step is, activists have warned that it will not change the high prevalence rates of the procedure in Nigeria -- or the rest of the continent -- overnight. As much as the legislation sends a clear message about impunity and provides activists with the legal framework to hold the government to account, criminalization of the entrenched practice still has its limitations, according to Stella Mukasa, the director of gender, violence and rights at the International Center for Research on Women.

“While legal safeguards are an important step towards ending FGM, they are not enough to eliminate it,” she wrote in a commentary for the Guardian. “Ending violence against women and girls requires investment, not just laws written in statute books. This is why we must emphasize community engagement, with a view towards shifting social norms, as a critical component of the eradication of FGM.”

The challenge of shifting social norms has been underscored in the case of other African countries like Egypt, where the prevalence of FGM was recently revealed to be at roughly 92 percent among married women despite the practice being outlawed in 2008. More than half of women surveyed by the government said they continued to be in favor of FGM because they viewed it as being in accordance with their cultural and religious traditions.