"Shadow fleet" refers to the collective of ships used by countries that have sanctions against them, like Russia, to transport commodities around the world. These ships pose threats to global and environmental security because they skirt international maritime law. So what can be done about them?Today on the show, we explain what exactly makes the shadow fleet so dangerous and why there are surprisingly limited options for how to deal with these problem ships.*For sponsor-free episodes of The Indicator from Planet Money, subscribe to Planet Money+ via Apple Podcasts or at plus.npr.org).Music by Drop Electric). Find us: TikTok), Instagram), Facebook), Newsletter).*Learn more about sponsor message choices: podcastchoices.com/adchoices)NPR Privacy Policy)