 Live from NPR News in Washington, I'm Janine Herbst. President Biden is hosting world leaders in Washington this week at a pivotal moment for himself, his campaign, and the future of the NATO alliance. NPR's Asma Khalid has more. Biden is welcoming NATO leaders later today with remarks at the Mellon Auditorium in Washington, D.C. It's the site of where the treaty that first created the transatlantic