Supporters of the presidential candidate Muhammadu Buhari and his All Progressive Congress (APC) party celebrate in Kano March 31, 2015. Three decades after seizing power in a military coup, Buhari became the first Nigerian to oust a president through the ballot box, putting him in charge of Africa's biggest economy and one of its most turbulent democracies.

© 2015 Reuters

Against the odds, Nigeria has succeeded in carrying out a mostly peaceful presidential election. The campaign was marked by bitter, divisive, and sometimes hateful rhetoric which left little hope that the contest would end without violence.

In elections in 2011, at least 800 people died as a result of violent protests and riots sparked by the rejection of the results. So far, such carnage has been avoided. Yesterday, Goodluck Jonathan ceded victory to his opponent Muhammadu Buhari, who is now the president-elect.

This good news should not obliterate the deep problems that bedevil Nigeria, including the Boko Haram insurgency in the northeast that is spilling across Nigeria’s borders, communal violence, corruption, and impunity for crimes by Nigerian security forces.

The test for Buhari will be to address these challenges in full respect of human rights. Buhari comes to power with questionable human rights credentials. He was the head of a military government that toppled the civilian administration of President Shehu Shagari in December 1983. His previous period as leader was marked by arbitrary arrests, restrictions on freedom of expression and the press, and retroactive criminal laws.

One of the surest ways for Buhari to demonstrate his evolution from a military ruler to a democratically elected president is to place respect for human rights at the center of his administration’s agenda.

He should start by making respect for human rights and humanitarian law a central pillar of military operations against Boko Haram. During his election campaign, Buhari vowed to defeat the Boko Haram threat. Standing with victims and holding Boko Haram to account for its brutal crimes is important but not a sufficient answer to the crisis. Nigerian security forces also need to be reined in.

According to witness interviews and media monitoring by Human Rights Watch, Boko Haram attacks are believed to have left at least 8,000 civilians dead since 2009 and more than one million people displaced.

In response to Boko Haram attacks, Nigerian security forces have often used excessive force. Hundreds of men and boys have been rounded up, detained in inhumane conditions, and in some cases physically abused because they were suspected of supporting Boko Haram. Some were executed. Many others have been forcibly disappeared, and security forces have burned civilian homes. Buhari should immediately stop such abuses by Nigerian security forces, ensure future operations comply with human rights and humanitarian law, order credible investigations of past crimes, and ensure that those responsible, including commanders, are held to account.