What’s behind recent Taliban attacks in Afghanistan?

At least 122 people have been killed in Kabul, the capital in Afghanistan, by recent attacks claimed by the Taliban. The latest was on Saturday, when an ambulance packed with explosives drove through a security checkpoint and detonated in the heart of the city. Doug Ollivant, who served as a director at the National Security Council under Presidents Bush and Obama, joins Hari Sreenivasan.