Russia's Cyber Attack: An Act of Espionage or War? Jeh Johnson's Perspective

Former US Homeland Security Secretary Jeh Johnson spent years trying to protect the United States against the kind of massive cyber attack that Russia carried out against American businesses and government agencies in the last year. But at what point should we view such a breach as more than a remarkable feat of espionage? When does it constitute an act of war? Johnson joins Ian Bremmer to discuss.