Rukmini Callimachi searches for humanity on the ISIS beat

After the international community and local security forces won a series of hard-fought victories against the Islamic State in recent years, ISIS is regrouping in Iraq, Syria, Libya and elsewhere. Rukmini Callimachi, a foreign correspondent for The New York Times who covers ISIS, joins Hari Sreenivasan to discuss her 10-part podcast “Caliphate” and her search for the militant group's motives.