More than 340 schoolboys were abducted from their boarding school in northwestern Nigeria last month, apparently by armed criminal gangs affiliated with the extremist group Boko Haram.

Though the boys were freed and reunited with their families a week later, the incident was a worrying sign that Boko Haram is expanding beyond its traditional base in northeastern Nigeria.

According to Bulama Bukarti, a Nigerian analyst at the Tony Blair Institute for Global Change and a non-resident senior associate at the Center for Strategic and International Studies, Boko Haram’s resurgence suggests the need for a more holistic, transnational approach to countering it. He joined the Trend Lines podcast this week to discuss this issue.