The U.S. Treasury Department is sanctioning six people and seven companies with links to Iranian-backed Hezbollah. In a statement Secretary Steve Mnuchin called Hezbollah “Iran’s primary proxy used to undermine legitimate Arab governments across the Middle East.”

Why it matters: The U.S. is working to limit Iran’s influence in the region, per the AP. The U.S. estimates Iran funds Hezbollah with $700 million annually, the AP reports. “The Administration is determined to expose and disrupt Hizballah’s networks, including those across the Middle East and West Africa, used to fund their illicit operations,” Mnuchin said.

Catch up quick: Hezbollah, founded in 1980, has long targeted Israel's army with Iran's financial and political support, but Hezbollah has been expanding its operations in recent years, NYT's Ben Hubbard writes: "It has sent legions of fighters to Syria. It has sent trainers to Iraq. It has backed rebels in Yemen. And it has helped organize a battalion of militants from Afghanistan that can fight almost anywhere."