The word sanctions gets tossed around a lot. The U.S. has sanctions on Iran, Russia, and even Cuba dating back to the Cold War. It’s the go-to way to isolate and starve a bad actor, using money.

This week, the U.S. and the E.U. tightened the screws on Russia with even more sanctions.

So how do these things work, anyway?

To find out we met up with economist Sheryl King, director at Roubini Global Economics, outside the United Nations to explain their global impact.