 Valley, thanks so much. It's always a pleasure talking to you. Thank you. Valley Nassar is a professor of Middle East Studies at Johns Hopkins University. Next, the mystery of a geologist in Arizona who's still missing three years after he disappeared near Phoenix. Despite leads and tips from the public, authorities say they have no idea what happened to 24-year-old Daniel Robinson. But Robinson's father has not stopped looking. NPR's Jonathan Franklin reports.