Is America safer since 9/11?

20 years have passed since 9/11, but is the US any safer? As the Taliban regains control in Afghanistan, was the War on Terror a failure or has it kept America safe from harm? And how did US allies feel as the last American planes left Kabul? On GZERO World, Ian Bremmer speaks to two people who have had a hand in crafting global policy since the towers fell: Michael Chertoff, who served as Secretary of the US Department of Homeland Security under President George Bush; and Rory Stewart, who worked extensively in Afghanistan in his role as UK Secretary of State for International Development and beyond.