How flags unite (and divide) us | Michael Green

Flags are one of the simplest yet most powerful pieces of design ever conceived. They can make us swell with pride, burn with hatred -- and even inspire people to die or kill in their name, says vexillologist Michael Green. Take a brief walk through history as Green explores the symbolic fervor behind flags that unify and divide, inviting us to imagine a future where we can come together under one collective identity: humanity.