To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Share Embed Share URL Video File Node URL Embed Code <iframe title="MRC TV video player" width="640" height="360" src="https://www.mrctv.org/embed/117456" allowfullscreen></iframe> NBC's Tom Brokaw called out Joe Biden for laughing and smiling while debating the "very serious" issue of foreign policy with Iran."I just don't think you should be laughing during a discussion about thermonuclear war with Iran," he insisted.