For months, Ukraine pressed western allies for state-of-the-art tanks. For months, Germany and the U.S. resisted. That changed Wednesday.Both countries have now promised to send tanks to Ukraine. The German-made Leopard II and American-made Abrams tanks are considered the best in the world.NPR's Rob Schmitz in Berlin and Greg Myre in Washington explain how Ukraine's allies changed their minds.In participating regions, you'll also hear a local news segment to help you make sense of what's going on in your community.Email us at considerthis@npr.org.