The Red Sea is the most trafficked trade route in the world, and now the US Navy and a group of militant Houthi rebels are going to war over it. The Houthis are attacking ships it says are linked to Israel and its allies; America is desperately trying to stop them. I mean, America might not get directly involved in the Israel-Gaza conflict, but you bet they'll protect their trade routes. The stakes couldn't be higher — if the US can't prove they have this under control, plenty of other groups around the world might decide to try their hand at blocking global trade as well. Editor's note: This introduction has been edited to clarify that not only Israeli ships have been targeted in Houthi attacks. Subscribe to If You're Listening on the ABC Listen app. Check out our series on YouTube: https://www.youtube.com/watch?v=OYJFHtTYc0g