Is the US war on ISIS legal? Today, we learn about one Army captain doesn't think so, because Congress hasn't officially signed off on the war against the extremist group. And he's suing to prove his point. Also, a community living outside Medellín, Colombia, has converted to Orthodox Judaism. Before that, the members belonged to a Protestant megachurch. Plus, Marco speaks with cellist Yo-Yo Ma about his Silk Road project, and how it's helped foster new friendships, and new musical collaborations around the globe, over the years.