Russian President Vladimir Putin arrived in North Korea for his first visit in 24 years and pledged strong support. We talk to Naoko Aoki, an associate political scientist at the RAND Corporation. June 19th is the U.S. holiday known as Juneteenth, which marks the day in 1865 when slavery ended in the former Confederate states of the American Civil War. U.S. lawmakers grilled Boeing's chief executive Tuesday about the company's plans to fix its manufacturing problems. Nvidia passes Microsoft to become the world’s most valuable company.