China agrees to crack down on chemicals used in fentanyl

China is one of the biggest sources of precursor chemicals used by Mexican cartels to make fentanyl. Much of that synthetic opioid ends up in the US, and fentanyl overdoses are currently the leading cause of death for Americans between the ages of 18 and 45. Now, Beijing has agreed to step up control of the production of some of those chemicals. Host Marco Werman gets analysis from Zongyuan Zoe Liu, a fellow at the Council on Foreign Relations.