Secretary of State Mike Pompeo announced on Monday that the US would no longer grant waivers that allow countries to import oil from Iran. He said, “We will no longer grant any exemptions, we are going to zero.” But at least one of Iran’s customers, China, is expected to keep buying oil despite economic threats from the US. Host Marco Werman learns how oil shipments would be verified in a conversation with Samir Madani of TankerTrackers.com, a research company that monitors oil tankers around the globe.