'Fortress' Russia put to the test

The U.S. is putting Russia's defense plan against sanctions to the test. Meanwhile, Russia's role as a huge exporter of oil and natural gas could cause ripple effects throughout the global economy. | Subscribe to our weekly newsletter <a href="https://www.npr.org/newsletter/money?utm_source=rss_feed_copy&utm_medium=podcast&utm_term=planet_money">here</a>.