Secondary Tariffs Make Entry as a New Trade Weapon

President Donald Trump appeared to invent a new weapon of economic statecraft on Monday by threatening what he dubbed "secondary tariffs" on countries that buy oil from Venezuela to choke off its oil trade with other nations.

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Francisco Monaldi, director of the Latin American energy policy at Rice University's Baker Institute for Public Policy in Houston. "How is it enforceable? It's unclear of course."

With the threat, Trump appeared to be inventing a combination of tariffs and what are known as secondary sanctions, the financial punishments that can be imposed on other countries or people for doing business with sanctioned entities.